Tootfinder

Oooh, cool, @…'s vacuum table project made HAD!
https://hackaday.com/2024/03/31/modular-vacuum-table-custom-fits-t…

Israel’s reluctance to fill the current leadership vacuum in northern Gaza formed the backdrop to the chaos that led to the deaths on Thursday of dozens of Palestinians on the Gazan coast, analysts and aid workers have said.
More than 100 were killed and 700 injured, Gazan health officials said, after thousands of hungry civilians rushed at a convoy of aid trucks, leading to a stampede and prompting Israeli soldiers to fire at the crowd.
The immediate causes of the chaos were ext…

Lack of Plan for Governing Gaza Formed Backdrop to Deadly Convoy Chaos
Israel has no clear plan for governing Gaza. That is a particular problem in the north, where the fighting has ebbed, and where a deadly stampede occurred on Thursday around an aid convoy.

#Roomba

Their mission is not so much to have their lies accepted as it is to destroy truth. They thrive and prosper in that vacuum.

This https://arxiv.org/abs/2401.15809 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Particle dynamics in spherically symmetric electro-vacuum instantons
In this paper, we study the geodesic motion in spherically symmetric electro-vacuum Euclidean solutions of the Einstein equation. There are two kinds of such solutions: the Euclidean Reissner-Nordström (ERN) metrics, and the Bertotti-Robinson-like (BR) metrics, the latter having constant Kretschmann scalar. First, we derive the motion equations for the ERN spacetime and we generalize the results of Battista-Esposito, showing that all orbits in as ERN spacetime are unbounded if and only if it h…

On the inefficiency of fermion level-crossing under the parity-violating spin-2 gravitational field
Kohei Kamada, Jun'ya Kume
https://arxiv.org/abs/2404.19726 https://arxiv.org/pdf/2404.19726
arXiv:2404.19726v1 Announce Type: new
Abstract: Gravitational chiral anomaly connects the topological charge of spacetime and the chirality of fermions. It has been known that the chirality is carried by the particles (or the excited states) and also by vacuum. While the gravitational anomaly equation has been applied to cosmology, distinction between these two contributions has been rarely discussed. In the study of gravitational leptogenesis, for example, lepton asymmetry associated with the chiral gravitational waves sourced during inflation is evaluated only by integrating the anomaly equation. How these two contributions are distributed has not been seriously investigated. Meanwhile, a dominance of vacuum contribution is observed in some specific types of Bianchi spacetime with parity-violating gravitational fields, whose application to cosmology is not straightforward. One may wonder whether such a vacuum dominance takes place also in the system with chiral gravitational waves around the flat background, which is more suitable for application to realistic cosmology. In this work, we apply an analogy between U(1) electromagnetism and the weak gravity to the spacetime that resembles the one considered in the gravitational leptogenesis scenario. This approach allows us to obtain intuitive understanding of the fermion chirality generation under the parity-violating spin-2 gravitational field. By assuming the emergence of Landau level-like dispersion relation in our setup, we conjecture that level-crossing does not seem to be efficient while the charge accumulation in the vacuum likely takes place. Phenomenological implication is also discussed in the context of gravitational leptogenesis.

#Spam des Tages: »Exklusive Miele – Triflex HX2 vacuum cleaner Belohnungen für Sie«
http://spam.tamagothi.de/?p=24991
Achtung, diese Spam ist überdurchschnittlich dumm.

This https://arxiv.org/abs/2402.18422 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Generalised Hydrodynamics description of the Page curve-like dynamics of a freely expanding fermionic gas
We consider an analytically tractable model that exhibits the main features of the Page curve characterizing the evolution of entanglement entropy during evaporation of a black hole. Our model is a gas of non-interacting fermions on a lattice that is released from a box into the vacuum. More precisely, our Hamiltonian is a tight-binding model with a defect at the junction between the filled box and the vacuum. In addition to the entanglement entropy we consider several other observables, such a…

This https://arxiv.org/abs/2312.17313 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Emerging entanglement on network histories
We show that quantum fields confined to Lorentzian histories of freely falling networks in Minkowski spacetime probe entanglement properties of vacuum fluctuations that extend unrestricted across spacetime regions. Albeit instantaneous field configurations are localized on one-dimensional edges, angular momentum emerges on these network histories and establish the celebrated area scaling of entanglement entropy.

This https://arxiv.org/abs/2404.16337 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

Stability of the Standard Model vacuum with respect to vacuum tunneling to the Komatsu vacuum in the cMSSM
We investigate the stability of the Standard Model vacuum with respect to vacuum tunneling to the Komatsu vacuum, which exists when $m_L^2 + m_{H_u}^2<0$, in the cMSSM. Employing the numerical tools \verb|SARAH|, \verb|SPheno| and \verb|CosmoTransitions|, we scan and constrain the parameter space of the cMSSM up to 10 TeV. Regions excluded due to having a vacuum tunneling half-life less than the age of the observable universe are concentrated near the regions where…

#Spam des Tages: »Exklusive Miele – Triflex HX2 vacuum cleaner Belohnungen für Sie«
http://spam.tamagothi.de/?p=24991
Achtung, diese Spam ist überdurchschnittlich dumm.

First act for the new vacuum cleaner: pimp with the 3D-Printer #3Dprint #3Dprinting #3Ddruck
Model:

Characterization of Silicon Photomultiplier Photon Detection Efficiency at Liquid Nitrogen Temperature
S. Borden, J. A. Detwiler, W. Pettus, N. W. Ruof
https://arxiv.org/abs/2405.01529

Characterization of Silicon Photomultiplier Photon Detection Efficiency at Liquid Nitrogen Temperature
The detection of individual photons at cryogenic temperatures is of interest to many experiments searching for physics beyond the Standard Model. Silicon photomultipliers are often deployed in liquid argon or liquid xenon to detect scintillation light by either directly detecting the vacuum ultra-violet scintillation or by detecting light from fluorescent compounds that are used to shift the wavelength. Here we present results from an experimental setup that measures the photon detection effici…

Thermal stability and phase transformation of $\alpha$-, $\kappa(\epsilon)$-, and $\gamma$-Ga$_2$O$_3$ thin films to $\beta$-Ga$_2$O$_3$ under various ambient conditions
J. Tang, K. Jiang, P. Tseng, R. C. Kurchin, L. M. Porter, R. F. Davis
https://arxiv.org/abs/2405.00299

Thermal stability and phase transformation of $α$-, $κ(ε)$-, and $γ$-Ga$_2$O$_3$ thin films to $β$-Ga$_2$O$_3$ under various ambient conditions
Phase transitions in metastable $α$-, $κ(ε)$-, and $γ$-Ga$_2$O$_3$ films to thermodynamically stable $β$-Ga$_2$O$_3$ during annealing in air, N$_2$, and vacuum have been systematically investigated via in-situ high-temperature X-ray diffraction and scanning electron microscopy. These respective polymorphs exhibited thermal stability to around 471-525$^\circ$C, 773-825$^\circ$C, and 490-575$^\circ$C before transforming into $β$-Ga$_2$O$_3$, across all tested ambient conditions. Particular …

Q: "What would vacuum decay look like if it occurred far away and spread towards us?"
A: "If a patch of spacetime anywhere in the universe were to change state, the change would radiate from there to the rest of the universe as a sort of “shock front” that propagated at the speed of light. That means we wouldn’t see it coming. We wouldn’t see any effect from it at all, and when it washed over us, we’d simply cease to exist."
God: ARE YOU NOT ENTERTAINED?

Highly stable photoluminescence in vacuum-processed halide perovskite core-shell 1D nanostructures
Javier Castillo-Seoane, Lidia Contreras-Bernal, T. Cristina Rojas, Juan P. Espinos, Andres-Felipe Castro-Mendez, Juan-P. Correa-Baena, Angel Barranco, Juan R. Sanchez-Valencia, Ana Borras
https://arxiv.org/abs/2402.19269

Highly stable photoluminescence in vacuum-processed halide perovskite core-shell 1D nanostructures
Hybrid organometal halide perovskites (HP) present exceptional optoelectronic properties, but their poor long-term stability is a major bottleneck for their commercialization. Herein, we present a solvent-free approach to growing single-crystal organic nanowires (ONW), nanoporous metal oxide scaffolds, and HP to form a core@multishell architecture. The synthetic procedure is carried out under mild vacuum conditions employing thermal evaporation for the metal-free phthalocyanine (H2Pc) nanowires…

Dive deep into the world of #PostgreSQL with Devrim Gunduz at #SCaLE21x! Join us for a talk on "VACUUM: From your head down to your shoes".

Revisiting string-inspired running-vacuum models under the lens of light primordial black holes
Theodoros Papanikolaou, Charalampos Tzerefos, Spyros Basilakos, Emmanuel N. Saridakis, Nick E. Mavromatos
https://arxiv.org/abs/2402.19373

Revisiting string-inspired running-vacuum models under the lens of light primordial black holes
Light primordial black holes (PBHs) with masses $M_\mathrm{PBH}<10^9\mathrm{g}$ can interestingly dominate the Universe's energy budget and give rise to early matter-dominated (eMD) eras before Big Bang Nucleosyntesis (BBN). During this eMD era, one is met with an abundant production of induced gravitational waves (GWs) serving as a portal to constrain the underlying theory of gravity. In this work, we study this type of induced GWs within the context of string-inspired running-vaccuum models (…

Weighted Catalan convolution and $(q,2)$-Fock space
Yungang Lu
https://arxiv.org/abs/2402.19447 https://arxiv.org/pdf/2402.19447

Weighted Catalan convolution and $(q,2)$-Fock space
Motivated by the study of certain combinatorial properties of $(q,2)$-Fock space, we compute explicitly a sequence driven by the Catalan's convolution and parameterized by $1+q$. As an application of this explicit form, we calculate the number of pair partitions involved in the determination of the vacuum--moments of the field operator defined on the $(q,2)$-Fock space.

Heat capacity and quantum compressibility of dynamical spacetimes with thermal particle creation
Jen-Tsung Hsiang, Yu-Cun Xie, Bei-Lok Hu
https://arxiv.org/abs/2405.00360

Heat capacity and quantum compressibility of dynamical spacetimes with thermal particle creation
This work continues the investigation in two recent papers on the quantum thermodynamics of spacetimes, 1) placing what was studied in [1] for thermal quantum fields in the context of early universe cosmology, and 2) extending the considerations of vacuum compressibility of dynamical spaces treated in [2] to dynamical spacetimes with thermal quantum fields. We begin with a warning that thermal equilibrium condition is not guaranteed to exist or maintained in a dynamical setting and thus finite …

Stability of the Standard Model vacuum with respect to vacuum tunneling to the Komatsu vacuum in the cMSSM
Hyukjung Kim, Ewan D. Stewart, Heeseung Zoe
https://arxiv.org/abs/2404.16337

Stability of the Standard Model vacuum with respect to vacuum tunneling to the Komatsu vacuum in the cMSSM
We investigate the stability of the Standard Model vacuum with respect to vacuum tunneling to the Komatsu vacuum, which exists when $m_L^2 + m_{H_u}^2<0$, in the cMSSM. Employing the numerical tools \verb|SARAH|, \verb|SPheno| and \verb|CosmoTransitions|, we scan and constrain the parameter space of the cMSSM up to 10 TeV. Regions excluded due to having a vacuum tunneling half-life less than the age of the observable universe are concentrated near the regions where…

This https://arxiv.org/abs/2211.00769 has been replaced.
link: https://scholar.google.com/scholar?q=a

Instability of electroweak homogeneous vacua in strong magnetic fields
We consider the classical vacua of the Weinberg-Salam (WS) model of electroweak forces. These are no-particle, static solutions to the WS equations minimizing the WS energy locally. We study the WS vacuum solutions exhibiting a non-vanishing average magnetic field of strength $b$, and prove that (i) there is a magnetic field threshold $b_*$ such that for $b < b_*$, the vacua are translationally invariant (and the magnetic field is constant), while for $b > b_*$ they are not, (ii) for $b > b_*…

Global existence and geometry of constant mass aspect function foliation in perturbed Schwarzschild spacetime
Pengyu Le
https://arxiv.org/abs/2404.17137 https://arxiv.org/pdf/2404.17137
arXiv:2404.17137v1 Announce Type: new
Abstract: The constant mass function foliation has been shown useful for studying the null Penrose inequality on a null hypersurface, because of the monotonicity formula of Hawking mass along such a foliation. In this paper, we show the global existence of the constant mass aspect function foliation on a nearly spherically symmetric incoming null hypersurface, emanating from a spacelike surface near the apparent horizon to the past null infinity in a vacuum perturbed Schwarzschild spacetime. Moreover, we study the geometry of the constant mass aspect function foliation, by comparing with the spherically symmetric foliation in the Schwarzschild spacetime. The knowledge about the geometry of the foliation is essential for investigating the perturbation of the constant mass aspect function foliation, which is the core in the application to the null Penrose inequality for a vacuum perturbed Schwarzschild spacetime.

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Luis A. Anchordoqui, Ignatios Antoniadis, Dieter Lust, Neena T. Noble, Jorge F. Soriano
https://arxiv.org/abs/2404.17334

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Promptly after high-resolution experiments harbinger the field of precision cosmology low- and high-redshift observations abruptly gave rise to a tension in the measurement of the present-day expansion rate of the Universe ($H_0$) and the clustering of matter ($S_8$). The statistically significant discrepancies between the locally measured values of $H_0$ and $S_8$ and the ones inferred from observations of the cosmic microwave background assuming the canonical $Λ$ cold dark matter (CDM) cosmo…

Search for heavy neutral Higgs bosons decaying into a top quark pair in 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV with the ATLAS detector
ATLAS Collaboration
https://arxiv.org/abs/2404.18986 https://arxiv.org/pdf/2404.18986
arXiv:2404.18986v1 Announce Type: new
Abstract: A search for heavy pseudo-scalar ($A$) and scalar ($H$) Higgs bosons decaying into a top-quark pair ($t\bar{t}$) has been performed with 140 fb$^{-1}$ of proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=13$ TeV. Interference effects between the signal process and Standard Model (SM) $t\bar{t}$ production are taken into account. Final states with exactly one or exactly two electrons or muons are considered. No significant deviation from the SM prediction is observed. The results of the search are interpreted in the context of a two-Higgs-doublet model (2HDM) of type II in the alignment limit with mass-degenerate pseudo-scalar and scalar Higgs bosons ($m_A = m_H$) and the hMSSM parameterisation of the minimal supersymmetric extension of the Standard Model. Ratios of the two vacuum expectation values, $\tan\beta$, smaller than 3.49 (3.16) are excluded at 95% confidence level for $m_A = m_H = 400$ GeV in the 2HDM (hMSSM). Masses up to 1240 GeV are excluded for the lowest tested $\tan\beta$ value of 0.4 in the 2HDM. In the hMSSM, masses up to 950 GeV are excluded for $\tan\beta=1.0$. In addition, generic exclusion limits are derived separately for single scalar and pseudo-scalar states for different choices of their mass and total width.

CNN: Ukraine dismisses Russian claim about killing hundreds of Ukrainian soldiers with a 'vacuum bomb': https://benborges.xyz/2024/03/17/cnn-ukraine-dismisses.html

On the Electromagnetic Mass Dilemma
Qasem Exirifard, Alessio D'Errico, Ebrahim Karimi
https://arxiv.org/abs/2405.00071 https://ar…

On the Electromagnetic Mass Dilemma
We show that a charged sphere moving at a constant velocity $v$ exhibits a mass due to electromagnetic radiation, expressed as $4/(3+(v/c)^2) (E/c^2)$, where $E$ is the electromagnetic energy and $c$ the speed of light in vacuum. Our finding reconciles the longstanding mismatch between the electromagnetic mass calculated from the classical electrodynamics' $4/3 (E/c^2)$ and the relativistic theory.

This https://arxiv.org/abs/2312.04352 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Gravitational Multipoles in Five Dimensions
We define gravitational mass and current multipoles for five-dimensional, stationary, and asymptotically flat vacuum metrics. We do this by generalizing Thorne's asymptotically Cartesian and mass-centered (ACMC) coordinate formalism to five dimensions, and prove that the multipoles defined in this way are unambiguously well-defined. Further, these two towers of multipole tensors, in the case of biaxial symmetry, reduce to a tower of mass multipoles $M_\ell$, and two separate towers of current o…

This https://arxiv.org/abs/2401.09829 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Polarized QED Cascades over Pulsar Polar Caps
The formation of $e^\pm$ plasmas within pulsar magnetospheres through quantum electrodynamics (QED) cascades in vacuum gaps is widely acknowledged. This paper aims to investigate the effect of photon polarization during the QED cascade occurring over the polar cap of a pulsar. We employ a Monte Carlo-based QED algorithm that accurately accounts for both spin and polarization effects during photon emission and pair production in both single-particle and particle-in-cell (PIC) simulations. Our fi…

This https://arxiv.org/abs/2311.17152 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

On the Quantum Bousso Bound in JT gravity
We prove the Strominger-Thompson quantum Bousso bound in the infinite class of conformal vacua in semiclassical JT gravity, with postive or negative cosmological constant. The Bousso-Fisher-Leichenauer-Wall quantum Bousso bound follows from an analogous derivation, requiring only initial quantum non-expansion. In this process, we show that the quantity ${2πk^μk^ν<:T_{μν}:>-S''-\frac{6}{c}(S')^2}$ vanishes in any vacuum state, entailing a stronger version of Wall's quantum null energy condi…

So. My vacuum cleaner speaks.
In European Portuguese.
I’m still yet to decide wether or not I like this feature.
I’ll leave it enabled for now.

Stellarator equilibrium axis-expansion to all orders in distance from the axis for arbitrary plasma beta
W. Sengupta, E. Rodriguez, R. Jorge, M. Landreman A. Bhattacharjee
https://arxiv.org/abs/2402.17034

Stellarator equilibrium axis-expansion to all orders in distance from the axis for arbitrary plasma beta
A systematic theory of the asymptotic expansion of the magnetohydrodynamic (MHD) equilibrium in the distance from the magnetic axis is developed to include arbitrary smooth currents near the magnetic axis. Compared to the vacuum and the force-free system, an additional magnetic differential equation must be solved to obtain the pressure-driven currents. It is shown that there exist variables in which the rest of the MHD system closely mimics the vacuum system. Thus, a unified treatment of MHD f…

This https://arxiv.org/abs/2401.16976 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Particle creation in left-handed metamaterial transmission lines
Transmission lines are excellent examples of quantum simulators of quantum fields. By appropriately driving specific circuit elements, these devices can reproduce relativistic and quantum such as particle creation due to the non-adiabatic stimulation of the quantum vacuum. We investigate particle creation in left-handed transmission lines induced by the modulation of the Josephson energy in superconducting quantum interference devices. Our results show that, as a consequence of the peculiar dis…

Locating heating channels of the solar corona in a plage region with the aid of high-resolution 10830 \AA\ filtergrams
Parida Hashim, Fangyu Xu, Ya Wang, Weijie Men, Jinhua Shen, Yingna Su, Jianping Li, Zhenyu Jin, Haisheng Ji
https://arxiv.org/abs/2402.18077

Locating heating channels of the solar corona in a plage region with the aid of high-resolution 10830 Å filtergrams
In this paper, with a set of high-resolution He I 10830 Å filtergrams, we select an area in a plage, very likely an EUV moss area, as an interface layer to follow the clues of coronal heating channels down to the photosphere. The filtergrams are obtained from the 1-meter aperture New Vacuum Solar Telescope (NVST). We make a distinction between the darker and the brighter regions in the selected area and name the two regions enhanced absorption patches (EAPs) and low absorption patches (LAPs). …

Brian Merchant with an important comment on OpenAI's sora:
" It’s not that Sora is generating new and amazing scenes based on the words you’re typing — it’s automating the act of stitching together renderings of extant video and images. Which is not uncool, in a vacuum! It’s indeed impressive that technology can do this.
But consider why it’s not being presented that way. For one, it just sounds boring, and is less likely to inspire the Emiratis to give Sam Altman billio…

Let's not do this again, please
OpenAI's text-to-video generator Sora is being hyped as a game-changer by an industry at a crossroads. This time we should know better

This https://arxiv.org/abs/2311.15981 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

Quantum kinetic approach to the Schwinger production of scalar particles in an expanding universe
We study the Schwinger pair creation of scalar charged particles by a homogeneous electric field in an expanding universe in the quantum kinetic approach. We introduce an adiabatic vacuum for the scalar field based on the Wentzel-Kramers-Brillouin solution to the mode equation in conformal time and apply the formalism of Bogolyubov coefficients to derive a system of quantum Vlasov equations for three real kinetic functions. Compared to the analogous system of equations previously reported in th…

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Luis A. Anchordoqui, Ignatios Antoniadis, Dieter Lust, Neena T. Noble, Jorge F. Soriano
https://arxiv.org/abs/2404.17334

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Promptly after high-resolution experiments harbinger the field of precision cosmology low- and high-redshift observations abruptly gave rise to a tension in the measurement of the present-day expansion rate of the Universe ($H_0$) and the clustering of matter ($S_8$). The statistically significant discrepancies between the locally measured values of $H_0$ and $S_8$ and the ones inferred from observations of the cosmic microwave background assuming the canonical $Λ$ cold dark matter (CDM) cosmo…

This https://arxiv.org/abs/2402.07056 has been replaced.
initial toot: https://mastoxiv.page/@ar…

Efficient ($\sim$10$\%$) Generation of Vacuum Ultraviolet Femtosecond Pulses via Four-Wave Mixing in Hollow-Core Fibers
We report the generation of the 5th harmonic of Ti:sapphire, at 160 nm, with more than 4~$μ$J of pulse energy, and a pulse length of 37 fs with a 1 kHz repetition rate. The VUV pulses are produced using Four-Wave Difference Frequency Mixing (FWDFM) in a helium-filled stretched Hollow-Core Fiber (HCF), driven by a pump at 267 nm and seeded at 800 nm. Guided by simulations using Luna.jl, we are able to optimize the process carefully. The result is a conversion efficiency of $\sim$10$\%$ from the…

A look at the proliferation of gimmicky online crypto-certification programs, as the lack of a well recognized professional crypto accreditation leaves a vacuum (Olga Kharif/Bloomberg)
https://www.bloomberg.com/news/articles/20

Bitcoin: Become a “Certified Cryptocurrency Expert,” or CCE for $229
To pass the chartered financial analyst exams and put the “CFA” letters on your resumè, at least 900 hours of study are recommended. Hitting the books for 300 to 400 hours is advised for the certified public accountant exam, which is usually taken by prospective CPAs who have completed an undergraduate degree in the subject.

This https://arxiv.org/abs/2308.03156 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Vanishing viscosity limit to the planar rarefaction wave with vacuum for 3-D full compressible Navier-Stokes equations with temperature-dependent transport coefficients
In this paper, we construct a family of global-in-time solutions of the 3-D full compressible Navier-Stokes (N-S) equations with temperature-dependent transport coefficients (including viscosity and heat-conductivity), and show that at arbitrary times {and arbitrary strength} this family of solutions converges to planar rarefaction waves connected to the vacuum as the viscosity vanishes in the sense of $L^\infty(\R^3)$. We consider the Cauchy problem in $\R^3$ with perturbations of the infinite…

The free energy of Dirac's vacuum in purely magnetic fields
Umberto Morellini
https://arxiv.org/abs/2404.12733 https://arxiv.org/…

The free energy of Dirac's vacuum in purely magnetic fields
The QED vacuum is a non-linear polarisable medium rather than an empty space. In this work, we present the first rigorous derivation of the one-loop effective magnetic Lagrangian at positive temperature, a non-linear functional describing the free energy of quantum vacuum in a classical magnetic field. We start by properly defining the free energy functional using the Pauli-Villars regularisation technique in order to remove the worst ultraviolet divergence which represents a well known issue o…

This https://arxiv.org/abs/2402.17458 has been replaced.
initial toot: https://mastoxiv.page/@a…

Field, frequency and temperature dependence of the surface resistance of nitrogen diffused niobium superconducting radio frequency cavities
We report the RF performance of several single-cell superconducting radio-frequency cavities subjected to low temperature heat treatment in nitrogen environment. The cavities were treated at temperature 120 - 165 C for an extended period of time (24 - 48 hours) either in high vacuum or in a low partial pressure of ultra-pure nitrogen. The improvement in Q0 with a Q-rise was observed when nitrogen gas was injected at 300 C during the cavity cooldown from 800 C and held at 165 C, without any degr…

This https://arxiv.org/abs/2310.13109 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

The four-loop $β$-function from vacuum supergraphs and the NSVZ relation for ${\cal N}=1$ SQED regularized by higher derivatives
In ${\cal N}=1$ SQED with $N_f$ flavors regularized by higher derivatives we obtain the four-loop beta function using a method based on calculating vacuum supergraphs. For this purpose we use a special C++ program which obtain contributions to the $β$-function from supergraphs without external legs in the form of integrals of double total derivatives. After that the result was compared with the three-loop anomalous dimension calculated earlier. We explicitly check the NSVZ relation in this ord…

Vacuum Petrov type D horizons of non-trivial $U(1)$ bundle structure over Riemann surfaces with genus $> 0$
Jerzy Lewandowski, Maciej Ossowski
https://arxiv.org/abs/2403.19383 …

Vacuum Petrov type D horizons of non-trivial $U(1)$ bundle structure over Riemann surfaces with genus $> 0$
We consider isolated horizons (Killing horizons up to the second order) whose null flow has the structure of a U(1) principal fiber bundle over a compact Riemann surface. We impose the vacuum Einstein equations (with the cosmological constant) and the condition that the spacetime Weyl tensor is of Petrov D type on the geometry of the horizons. We derive all the solutions in the case when the genus of the surface is $>1$. By doing so for all the non-trivial bundles, we complete the classificatio…

Uniqueness of static vacuum asymptotically flat black holes and equipotential photon surfaces in $n 1$ dimensions \`a la Robinson
Carla Cederbaum, Albachiara Cogo, Benedito Leandro, Jo\~ao Paulo dos Santos
https://arxiv.org/abs/2403.14422

Uniqueness of static vacuum asymptotically flat black holes and equipotential photon surfaces in $n+1$ dimensions à la Robinson
In this paper, we generalize to higher dimensions Robinson's approach to proving the uniqueness of connected $(3+1)$-dimensional static vacuum asymptotically flat black hole spacetimes. In consequence, we prove geometric inequalities for connected $(n+1)$-dimensional static vacuum asymptotically flat black holes, recovering results by Agostiniani and Mazzieri. We also obtain similar geometric inequalities for connected $(n+1)$-dimensional static vacuum asymptotically flat equipotential photon s…

Locating heating channels of the solar corona in a plage region with the aid of high-resolution 10830 \AA\ filtergrams
Parida Hashim, Fangyu Xu, Ya Wang, Weijie Men, Jinhua Shen, Yingna Su, Jianping Li, Zhenyu Jin, Haisheng Ji
https://arxiv.org/abs/2402.18077

Locating heating channels of the solar corona in a plage region with the aid of high-resolution 10830 Å filtergrams
In this paper, with a set of high-resolution He I 10830 Å filtergrams, we select an area in a plage, very likely an EUV moss area, as an interface layer to follow the clues of coronal heating channels down to the photosphere. The filtergrams are obtained from the 1-meter aperture New Vacuum Solar Telescope (NVST). We make a distinction between the darker and the brighter regions in the selected area and name the two regions enhanced absorption patches (EAPs) and low absorption patches (LAPs). …

#Vacuum

Tunable coupling of a quantum phononic resonator to a transmon qubit with flip-chip architecture
Xinhui Ruan, Li Li, Guihan Liang, Silu Zhao, Jia-heng Wang, Yizhou Bu, Bingjie Chen, Xiaohui Song, Xiang Li, He Zhang, Jinzhe Wang, Qianchuan Zhao, Kai Xu, Heng Fan, Yu-xi Liu, Jing Zhang, Zhihui Peng, Zhongcheng Xiang, Dongning Zheng
https://

Tunable coupling of a quantum phononic resonator to a transmon qubit with flip-chip architecture
A hybrid system with tunable coupling between phonons and qubits shows great potential for advancing quantum information processing. In this work, we demonstrate strong and tunable coupling between a surface acoustic wave (SAW) resonator and a transmon qubit based on galvanic-contact flip-chip technique. The coupling strength varies from $2π\times$7.0 MHz to -$2π\times$20.6 MHz, which is extracted from different vacuum Rabi oscillation frequencies. The phonon-induced ac Stark shift of the qub…

Symmetry restoration and vacuum decay from accretion around black holes
James Marsden, Josu C. Aurrekoetxea, Katy Clough, Pedro G. Ferreira
https://arxiv.org/abs/2403.17595

Symmetry restoration and vacuum decay from accretion around black holes
Vacuum decay and symmetry breaking play an important role in the fundamental structure of the matter and the evolution of the universe. In this work we study how the purely classical effect of accretion of fundamental fields onto black holes can lead to shells of symmetry restoration in the midst of a symmetry broken phase. We also show how it can catalyze vacuum decay, forming a bubble that expands asymptotically at the speed of light. These effects offer an alternative, purely classical mecha…

Effective Potential and Vacuum Stability in the Litim-Sannino Model
Tom Steudtner
https://arxiv.org/abs/2402.16950 https://arxiv.org/…

Effective Potential and Vacuum Stability in the Litim-Sannino Model
We revisit the scalar potential in the Litim-Sannino model. We compute for the first time the full quantum corrections to the classical potential and show that they significantly ameliorate the stability analysis at the UV fixed point. The quantum effective potential is computed at two-loop order and the numerical precision is further improved using resummations and parameter optimisations. As a result, we find a consistent widening of the UV conformal window across various approximations.

Simulating vacuum arc initiation by coupling emission, heating and plasma processes
Roni Koitermaa, Andreas Kyritsakis, Tauno Tiirats, Veronika Zadin, Flyura Djurabekova
https://arxiv.org/abs/2402.08404

Simulating vacuum arc initiation by coupling emission, heating and plasma processes
Vacuum arcing poses significant challenges for high-field vacuum devices, underscoring the importance of understanding it for their efficient design. A detailed description of the physical mechanisms involved in vacuum arcing is yet to be achieved, despite extensive research. In this work, we further develop the modelling of the physical processes involved in the initiation of vacuum arcing, starting from field emission and leading to plasma onset. Our model concurrently combines particle-in-ce…

This https://arxiv.org/abs/2311.14791 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

The QCD vacuum as a disordered chromomagnetic condensate
An attempt is made to describe from first principles the large-scale structure of the confining vacuum in quantum chromodynamics. Starting from our previous variational studies of the SU(2) pure gauge theory in an external Abelian chromomagnetic field and extending the Feynman's qualitative analysis in (2+1)-dimensional SU(2) gauge theory, we show that the SU(3) vacuum in three-space and one-time dimensions behaves like a disordered chromomagnetic condensate. Color confinement is assured by the…

This https://arxiv.org/abs/2402.07056 has been replaced.
initial toot: https://mastoxiv.page/@ar…

Efficient ($\sim$10$\%$) Generation of Vacuum Ultraviolet Femtosecond Pulses via Four-Wave Mixing in Hollow-Core Fibers
We report the generation of the 5th harmonic of Ti:sapphire, at 160 nm, with more than 4~$μ$J of pulse energy, and a pulse length of 37 fs with a 1 kHz repetition rate. The VUV pulses are produced using Four-Wave Difference Frequency Mixing (FWDFM) in a helium-filled stretched Hollow-Core Fiber (HCF), driven by a pump at 267 nm and seeded at 800 nm. Guided by simulations using Luna.jl, we are able to optimize the process carefully. The result is a conversion efficiency of $\sim$10$\%$ from the…

Vacuum Rabi splitting as a manifestation of virtual two-mode squeezing: Extracting the squeezing parameters from frequency shifts
Karol Gietka
https://arxiv.org/abs/2403.12177

Vacuum Rabi splitting as a manifestation of virtual two-mode squeezing: Extracting the squeezing parameters from frequency shifts
Vacuum Rabi splitting relies on symmetrical splitting of the common resonance frequency of atoms and the cavity in which the atoms reside. In this work, we argue that vacuum Rabi splitting is a manifestation of virtual light-matter two-mode squeezing. We establish a connection between squeezing parameters of virtual excitations and frequency shifts of the physical modes. To this end, we use the mapping between the Dicke model and two interacting harmonic oscillators, which we analyze in the fra…

This https://arxiv.org/abs/2401.12054 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Twisting asymptotic symmetries and algebraically special vacuum solutions
In this paper, we study asymptotic symmetries and algebraically special exact solutions in the Newman-Penrose formalism. Removing the hypersurface orthogonal condition in the well studied Newman-Unti gauge, we obtain a generic asymptotic solution space which includes all possible origins of propagating degree of freedom. The asymptotic symmetry of the generalized system extends the Weyl-BMS symmetry by two independent local Lorentz transformations with non-trivial boundary charges, which reveal…

#Vacuum

This https://arxiv.org/abs/2402.00784 has been replaced.
link: https://scholar.google.com/scholar?q=a

High-resolution MHz time- and angle-resolved photoemission spectroscopy based on a tunable vacuum ultraviolet source
Time and angle-resolved photoemission spectroscopy (trARPES) allows direct mapping of the electronic band structure and its dynamic response on femtosecond timescales. Here, we present a new ARPES system, powered by a new fiber-based femtosecond light source in the vacuum ultraviolet (VUV) range, accessing the complete first Brillouin zone for most materials. We present trARPES data on Au(111), polycrystalline Au, Bi2Se3 and TaTe2, demonstrating an energy resolution of 21 meV with a time resolu…

This https://arxiv.org/abs/2402.00056 has been replaced.
link: https://scholar.google.com/scholar?q=a

Pauli-Villars regularization of Kaluza-Klein Casimir energy with Lorentz symmetry
The Pauli-Villars regularization is appropriate to discuss the UV sensitivity of low-energy observables because it mimics how the contributions of new particles at high energies cancel large quantum corrections from the light particles in the effective field theory. We discuss the UV sensitivity of the Casimir energy density and pressure in an extra-dimensional model in this regularization scheme, and clarify the condition on the regulator fields to preserve the Lorentz symmetry of the vacuum s…

Simulating vacuum arc initiation by coupling emission, heating and plasma processes
Roni Koitermaa, Andreas Kyritsakis, Tauno Tiirats, Veronika Zadin, Flyura Djurabekova
https://arxiv.org/abs/2402.08404

Simulating vacuum arc initiation by coupling emission, heating and plasma processes
Vacuum arcing poses significant challenges for high-field vacuum devices, underscoring the importance of understanding it for their efficient design. A detailed description of the physical mechanisms involved in vacuum arcing is yet to be achieved, despite extensive research. In this work, we further develop the modelling of the physical processes involved in the initiation of vacuum arcing, starting from field emission and leading to plasma onset. Our model concurrently combines particle-in-ce…

Motion of test particles in quasi anti-de Sitter regular black holes
Dario Corona, Roberto Giamb\`o, Orlando Luongo
https://arxiv.org/abs/2402.18997 https:…

Motion of test particles in quasi anti-de Sitter regular black holes
We explore the characteristics of two novel regular spacetimes that exhibit a non-zero vacuum energy term, under the form of a (quasi) anti-de Sitter phase. Specifically, the first metric is spherical, while the second, derived by applying the generalized Newman-Janis algorithm to the first, is axisymmetric. We show that the equations of state of the effective fluids associated with the two metrics asymptotically tend to negative values, resembling quintessence. In addition, we study test parti…

Kinetic theory of vacuum pair production in uniform electric fields revisited
I. A. Aleksandrov, A. Kudlis, A. I. Klochai
https://arxiv.org/abs/2403.17204 …

Kinetic theory of vacuum pair production in uniform electric fields revisited
We investigate the phenomenon of electron-positron pair production from vacuum in the presence of a uniform time-dependent electric field of arbitrary polarization. Taking into account the interaction with the external classical background in a nonperturbative manner, we quantize the electron-positron field and derive a system of ten quantum kinetic equations (QKEs) showing that the previously-used QKEs are incorrect once the external field rotates in space. We employ then the Wigner-function f…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
Jing-Yu Ran, Bao Wang, Jun-Jie Wei
https://arxiv.org/abs/2404.17154 <…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
A hypothetical photon mass, $m_γ$, can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure--redshift measurements of fast radio bursts (FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard $Λ$CDM cos…

Trans-series from condensates
Marcos Marino, Ramon Miravitllas
https://arxiv.org/abs/2402.19356 https://arxiv.org/pdf/2402.19356

Trans-series from condensates
The Shifman--Vainshtein--Zakharov (SVZ) sum rules provide a method to obtain trans-series expansions in many quantum field theories, in which exponentially small corrections are calculated by combining the operator product expansion with the assumption of vacuum condensates. In some solvable models, exact expressions for trans-series can be obtained from non-perturbative results, and this makes it possible to test the SVZ method by comparing its predictions to these exact trans-series. In this …

Kinetic theory of vacuum pair production in uniform electric fields revisited
I. A. Aleksandrov, A. Kudlis, A. I. Klochai
https://arxiv.org/abs/2403.17204 …

Kinetic theory of vacuum pair production in uniform electric fields revisited
We investigate the phenomenon of electron-positron pair production from vacuum in the presence of a uniform time-dependent electric field of arbitrary polarization. Taking into account the interaction with the external classical background in a nonperturbative manner, we quantize the electron-positron field and derive a system of ten quantum kinetic equations (QKEs) showing that the previously-used QKEs are incorrect once the external field rotates in space. We employ then the Wigner-function f…

Rotating galactic black holes
Chao Zhang, Guoyang Fu, Chunyu Zhang
https://arxiv.org/abs/2403.19933 https://arxiv.org/pdf/2403.19933<…

Rotating galactic black holes
The galactic black hole is a supermassive black hole located at the center of a galaxy surrounded by a dark matter halo. For the first time, we establish a generic, fully-relativistic formalism to calculate solutions of Einstein's gravity minimally coupled to an anisotropic fluid modeled by the Einstein cluster in axisymmetric, non-vacuum spacetimes, which are extensions of spherically-symmetric cases. These asymptotically flat spacetimes with regular horizons can describe the geometry of galax…

This https://arxiv.org/abs/2402.00784 has been replaced.
link: https://scholar.google.com/scholar?q=a

High-resolution MHz time- and angle-resolved photoemission spectroscopy based on a tunable vacuum ultraviolet source
Time and angle-resolved photoemission spectroscopy (trARPES) allows direct mapping of the electronic band structure and its dynamic response on femtosecond timescales. Here, we present a new ARPES system, powered by a new fiber-based femtosecond light source in the vacuum ultraviolet (VUV) range, accessing the complete first Brillouin zone for most materials. We present trARPES data on Au(111), polycrystalline Au, Bi2Se3 and TaTe2, demonstrating an energy resolution of 21 meV with a time resolu…

This https://arxiv.org/abs/2402.04320 has been replaced.
link: https://scholar.google.com/scholar?q=a

Semiclassics for the QCD vacuum structure through $T^2$-compactification with the baryon-'t Hooft flux
We study QCD vacuum structure with the topological $θ$ angle using a recently proposed semiclassical approach on $\mathbb{R}^2 \times T^2$ with the 't Hooft and baryon magnetic fluxes. Under the assumption of adiabatic continuity in this setup, the confining vacuum can be described by the dilute gas of center vortices. With this semiclassical approach, we derive the 2d effective description at small $T^2$ and successfully explain the reasonable theta dependence of the QCD vacuum: In the one-fl…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
Jing-Yu Ran, Bao Wang, Jun-Jie Wei
https://arxiv.org/abs/2404.17154 <…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
A hypothetical photon mass, $m_γ$, can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure--redshift measurements of fast radio bursts (FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard $Λ$CDM cos…

This https://arxiv.org/abs/2312.06749 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

Electroweak Phase Transition with a Double Well Done Doubly Well
We revisit the electroweak phase transition in the scalar singlet extension of the standard model with a $\mathbb{Z}_2$ symmetry. In significant parts of the parameter space the phase transition occurs in two steps - including canonical benchmarks used in experimental projections for gravitational waves. Domain walls produced in the first step of the transition seed the final step to the electroweak vacuum, an effect which is typically neglected but leads to an exponentially enhanced tunnelling…

This https://arxiv.org/abs/2310.07058 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Ion Trap with In-Vacuum High Numerical Aperture Imaging for a Dual-Species Modular Quantum Computer
Photonic interconnects between quantum systems will play a central role in both scalable quantum computing and quantum networking. Entanglement of remote qubits via photons has been demonstrated in many platforms; however, improving the rate of entanglement generation will be instrumental for integrating photonic links into modular quantum computers. We present an ion trap system that has the highest reported free-space photon collection efficiency for quantum networking. We use a pair of in-va…

Enhancement of Entanglement via Josephson Parametric Amplifier in a Dual Cavity-Magnon System
Abdelkader Hidki, Abderrahim Lakhfif, Mostafa Nassik, Rizwan Ahmed, Amjad Sohail
https://arxiv.org/abs/2402.16042

Enhancement of Entanglement via Josephson Parametric Amplifier in a Dual Cavity-Magnon System
In the two microwave (MW) cross-shaped cavity magnon system, we describe a method to produce multipartite entanglement and quantum steering. To achieve squeezed states of the magnons, a Josephson parametric amplifier (JPA) creates a squeezed vacuum field that drives the two cavities. We theoretically demonstrate that the cavity-cavity entanglement can be generated at the resonance point, however, increasing the cavity and magnon decay rates generate the cavity-magnon entanglement. By changing t…

Bridging hadronic and vacuum structure by heavy quarkonia
Nicholas Miesch, Edward Shuryak, Ismail Zahed
https://arxiv.org/abs/2403.18700 https://

Bridging hadronic and vacuum structure by heavy quarkonia
We discuss the central and, mostly, spin-dependent potentials in heavy quarkonia $\bar b b, \bar c c$, with two goals in mind. The first is phenomenological: using the splitting between the 1S and 2S pairs, as well as the 1P and 2P quartet masses, we obtain very accurate values of all matrix elements of the spin-depepdent potentials. The second is theoretical: using standard wave functions, we compute these matrix elements, from perturbative, nonperturbative and ``string" contributions. The mod…

Enhancement of Entanglement via Josephson Parametric Amplifier in a Dual Cavity-Magnon System
Abdelkader Hidki, Abderrahim Lakhfif, Mostafa Nassik, Rizwan Ahmed, Amjad Sohail
https://arxiv.org/abs/2402.16042

Enhancement of Entanglement via Josephson Parametric Amplifier in a Dual Cavity-Magnon System
In the two microwave (MW) cross-shaped cavity magnon system, we describe a method to produce multipartite entanglement and quantum steering. To achieve squeezed states of the magnons, a Josephson parametric amplifier (JPA) creates a squeezed vacuum field that drives the two cavities. We theoretically demonstrate that the cavity-cavity entanglement can be generated at the resonance point, however, increasing the cavity and magnon decay rates generate the cavity-magnon entanglement. By changing t…

This https://arxiv.org/abs/2403.02230 has been replaced.
link: https://scholar.google.com/scholar?q=a

Conformally related vacuum gravitational waves, and their symmetries
A special conformal transformation which carries a vacuum gravitational wave into another vacuum one is built by using Möbius-redefined time. It can either transform a globally defined vacuum wave into a vacuum sandwich wave, or carry the gravitational wave into itself. The first type, illustrated by linearly and circularly polarized vacuum plane gravitational waves, permutes the symmetries and the geodesics. Our pp waves with conformal O(2,1) symmetry of the second type, which seem to ahve es…

An exact stationary axisymmetric vacuum solution within a metric--affine bumblebee gravity
A. A. Ara\'ujo Filho, J. R. Nascimento, A. Yu. Petrov, P. J. Porf\'irio
https://arxiv.org/abs/2402.13014

An exact stationary axisymmetric vacuum solution within a metric--affine bumblebee gravity
Within the framework of the spontaneous Lorentz symmetry breaking, we consider a metric--affine generalization of the gravitational sector of the Standard--Model Extension (SME), including the Lorentz--violating (LV) coefficients $u$ and $s^{μν}$. In this model, we derive the modified Einstein field equations in order to obtain a new axisymmetric vacuum spinning solution for a particular bumblebee's profile. Such a solution has the remarkable property of incorporating the effects of Lorentz s…

This https://arxiv.org/abs/2402.06404 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hept…

Vacuum Force and Confinement
We show that confinement of quarks and gluons can be explained by their interaction with the vacuum Abelian gauge field $A_{\sf{vac}}$, which is implicitly introduced by the canonical commutation relations and generates the vacuum force. The background gauge field $A_{\sf{vac}}$, linear in coordinates of $\mathbb{R}^3$, is inherently present in quantum mechanics: it is introduced during the canonical quantization of phase space $(T^*\mathbb{R}^3, ω)$ of a nonrelativistic particle, when a poten…

This https://arxiv.org/abs/2404.14480 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

Holography for Sp(2$N_c$) Gauge Dynamics: from Composite Higgs to Technicolour
We study Sp(2$N_c$) gauge dynamics with two Dirac fermion flavours in the fundamental representation. These strongly coupled systems underlie some composite Higgs models with a global symmetry breaking pattern SU(4)$\rightarrow$Sp(4), leading to a light quartet of pseudo-Goldstone bosons that can play the role of the Higgs. Including four-fermion interactions can rotate the vacuum to a technicolour breaking pattern. Using gauge/gravity duality, we study the underlying gauge dynamics. Our model …

This https://arxiv.org/abs/2402.03360 has been replaced.
link: https://scholar.google.com/scholar?q=a

Differential equation for the Uehling potential
The second-order differential equation for the Uehling potential is derived explicitly. The right side of this differential equation is a linear combination of the two Macdonald's functions $K_{0}(b r)$ and $K_{1}(b r)$. This central potential is of great interest in many QED problems, since it describes the lowest-order correction for vacuum polarization in few- and many-electron atoms, ions, muonic and bi-muonic atoms/ions as well as in other similar systems.

General vacuum solution of modified $F(G)$-gravity with Gauss-Bonnet term
Maria V. Shubina
https://arxiv.org/abs/2403.13919 https://a…

General vacuum solution of modified $F(G)$-gravity with Gauss-Bonnet term
In this paper we present a general vacuum solution of the modified Gauss-Bonnet gravity equations for the Friedmann-Lemaître-Robertson-Walker metric. We use an ansatz to reduce the gravitational equations to an ordinary differential equations for function $F=F(G)$. The solution obtained depends on an arbitrary function and is new. As an example we take an arbitrary function in the form of a power one and analyze the solutions for both $ F(G) $ and the main cosmological physical quantities as s…

This https://arxiv.org/abs/2403.00559 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

A new Wolfenstein-like expansion of lepton flavor mixing towards understanding its fine structure
Taking the tri-bimaximal flavor mixing pattern as a particular basis, we propose a new way to expand the $3\times 3$ unitary Pontecorvo-Maki-Nakagawa-Sakata (PMNS) lepton flavor mixing matrix $U$ in powers of the magnitude of its smallest element $ξ\equiv \left|U^{}_{e 3}\right| \simeq 0.149$. Such a Wolfenstein-like parametrization of $U$ allows us to easily describe the salient features and fine structures of flavor mixing and CP violation, both in vacuum and in matter.

This https://arxiv.org/abs/2402.04320 has been replaced.
link: https://scholar.google.com/scholar?q=a

Semiclassics for the QCD vacuum structure through $T^2$-compactification with the baryon-'t Hooft flux
We study QCD vacuum structure with the topological $θ$ angle using a recently proposed semiclassical approach on $\mathbb{R}^2 \times T^2$ with the 't Hooft and baryon magnetic fluxes. Under the assumption of adiabatic continuity in this setup, the confining vacuum can be described by the dilute gas of center vortices. With this semiclassical approach, we derive the 2d effective description at small $T^2$ and successfully explain the reasonable theta dependence of the QCD vacuum: In the one-fl…

General vacuum solution of modified $F(G)$-gravity with Gauss-Bonnet term
Maria V. Shubina
https://arxiv.org/abs/2403.13919 https://a…

General vacuum solution of modified $F(G)$-gravity with Gauss-Bonnet term
In this paper we present a general vacuum solution of the modified Gauss-Bonnet gravity equations for the Friedmann-Lemaître-Robertson-Walker metric. We use an ansatz to reduce the gravitational equations to an ordinary differential equations for function $F=F(G)$. The solution obtained depends on an arbitrary function and is new. As an example we take an arbitrary function in the form of a power one and analyze the solutions for both $ F(G) $ and the main cosmological physical quantities as s…

This https://arxiv.org/abs/1812.02089 has been replaced.
link: https://scholar.google.com/scholar?q=a

Scalar probes on wormholes in Lovelock theories with unique vacuum
In this paper we present a new family of wormhole geometries in Lovelock theories with a unique vacuum, and study their stability under scalar field perturbations. As the solutions already known in the literature for Chern-Simons gravity on AdS, the new wormholes are characterized by a single integration constant $ρ_{0}$, that parameterizes the contribution to the mass coming from each boundary, which cancel each other, leading to a new example of "mass without mass". The stability of these ne…

Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay
Shao-Feng Ge, Chui-Fan Kong, Alexei Y. Smirnov
https://arxiv.org/abs/2404.17352 htt…

Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay
The origin of neutrino masses remains unknown. Both the vacuum mass and the dark mass generated by the neutrino interactions with DM particles or fields can fit the current oscillation data. The dark mass squared is proportional to the DM number density and therefore varies on the galactic scale with much larger values around the Galactic Center. This affects the group velocity and the arrival time delay of core-collapse supernovae neutrinos. This time delay, especially for the $ν_e$ neutroniz…

Variable Hyperparameterized Gaussian Kernel using Displaced Squeezed Vacuum State
Vivek Mehta, Utpal Roy
https://arxiv.org/abs/2403.11560 https://

Variable Hyperparameterized Gaussian Kernel using Displaced Squeezed Vacuum State
There are schemes for realizing different types of kernels by quantum states of light. It is particularly interesting to realize the Gaussian kernel due to its wider applicability. A multimode coherent state can generate the Gaussian kernel with a constant value of hyperparameter. This constant hyperparameter has limited the application of the Gaussian kernel when it is applied to complex learning problems. We realize the variable hyperparameterized Gaussian kernel with a multimode-displaced sq…

Avoiding singularities in Lorentzian-Euclidean black holes: the role of atemporality
Salvatore Capozziello, Silvia De Bianchi, Emmanuele Battista
https://arxiv.org/abs/2404.17267 …

Avoiding singularities in Lorentzian-Euclidean black holes: the role of atemporality
We investigate a Schwarzschild metric exhibiting a signature change across the event horizon, which gives rise to what we term a Lorentzian-Euclidean black hole. The resulting geometry is regularized by employing the Hadamard partie finie technique, which allows us to prove that the metric represents a solution of vacuum Einstein equations. In this framework, we introduce the concept of atemporality as the dynamical mechanism responsible for the transition from a regime with a real-valued time …

Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay
Shao-Feng Ge, Chui-Fan Kong, Alexei Y. Smirnov
https://arxiv.org/abs/2404.17352 htt…

Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay
The origin of neutrino masses remains unknown. Both the vacuum mass and the dark mass generated by the neutrino interactions with DM particles or fields can fit the current oscillation data. The dark mass squared is proportional to the DM number density and therefore varies on the galactic scale with much larger values around the Galactic Center. This affects the group velocity and the arrival time delay of core-collapse supernovae neutrinos. This time delay, especially for the $ν_e$ neutroniz…

Vacuum Force and Confinement
Alexander D. Popov
https://arxiv.org/abs/2402.06404 https://arxiv.org/pdf/2402.06404

Vacuum Force and Confinement
We show that confinement of quarks and gluons can be explained by their interaction with the vacuum Abelian gauge field $A_{\sf{vac}}$, which is implicitly introduced by the canonical commutation relations and generates the vacuum force. The background gauge field $A_{\sf{vac}}$, linear in coordinates of $\mathbb{R}^3$, is inherently present in quantum mechanics: it is introduced during the canonical quantization of phase space $(T^*\mathbb{R}^3, ω)$ of a nonrelativistic particle, when a poten…

Revisiting Buchdahl transformations: New static and rotating black holes in vacuum, double copy, and hairy extensions
Jos\'e Barrientos, Adolfo Cisterna, Mokhtar Hassaine, Julio Oliva
https://arxiv.org/abs/2404.12194

Revisiting Buchdahl transformations: New static and rotating black holes in vacuum, double copy, and hairy extensions
This paper investigates Buchdahl transformations within the framework of Einstein and Einstein-Scalar theories. Specifically, we establish that the recently proposed Schwarzschild-Levi-Civita spacetime can be obtained by means of a Buchdahl transformation of the Schwarschild metric along the spacelike Killing vector. The study extends Buchdahl's original theorem by combining it with the Kerr-Schild representation. In doing so, we construct new vacuum-rotating black holes in higher dimensions wh…

Krylov Complexity in $2d$ CFTs with SL$(2,\mathbb{R})$ deformed Hamiltonians
Vinay Malvimat, Somnath Porey, Baishali Roy
https://arxiv.org/abs/2402.15835 h…

Krylov Complexity in $2d$ CFTs with SL$(2,\mathbb{R})$ deformed Hamiltonians
In this study, we analyze Krylov Complexity in two-dimensional conformal field theories subjected to deformed SL$(2,\mathbb{R})$ Hamiltonians. In the vacuum state, we find that the K-complexity exhibits a universal phase structure. The phase structure involves the K-complexity exhibiting an oscillatory behaviour in the non-heating phase, which contrasts with the exponential growth observed in the heating phase, while it displays polynomial growth at the phase boundary. Furthermore, we extend ou…

Rewording theoretical predictions at colliders with vacuum amplitudes
Selomit Ram\'irez-Uribe, Prasanna K. Dhani, German F. R. Sborlini, Germ\'an Rodrigo
https://arxiv.org/abs/2404.05491

Rewording theoretical predictions at colliders with vacuum amplitudes
We propose multiloop vacuum amplitudes as the optimal building blocks for efficiently assembling theoretical predictions at high-energy colliders. This hypothesis is strongly supported by the manifestly causal properties of the loop-tree duality (LTD) representation of a vacuum amplitude. The vacuum amplitude, acting as a kernel, encodes all the final states contributing to a given scattering or decay process through residues in the on-shell energies of the internal propagators. It also natural…

Krylov Complexity in $2d$ CFTs with SL$(2,\mathbb{R})$ deformed Hamiltonians
Vinay Malvimat, Somnath Porey, Baishali Roy
https://arxiv.org/abs/2402.15835 h…

Krylov Complexity in $2d$ CFTs with SL$(2,\mathbb{R})$ deformed Hamiltonians
In this study, we analyze Krylov Complexity in two-dimensional conformal field theories subjected to deformed SL$(2,\mathbb{R})$ Hamiltonians. In the vacuum state, we find that the K-complexity exhibits a universal phase structure. The phase structure involves the K-complexity exhibiting an oscillatory behaviour in the non-heating phase, which contrasts with the exponential growth observed in the heating phase, while it displays polynomial growth at the phase boundary. Furthermore, we extend ou…

This https://arxiv.org/abs/2310.12668 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Ultracompact horizonless objects in order-reduced semiclassical gravity
The backreaction of quantum fields in their vacuum state results in equilibrium structures that surpass the Buchdahl compactness limit. Such backreaction is encapsulated in the vacuum expectation value of the renormalized stress-energy tensor (RSET). In previous works we presented analytic approximations to the RSET, obtained by dimensional reduction, available in spherical symmetry, and showed that the backreaction-generated solutions described ultracompact fluid spheres with a negative mass i…

This https://arxiv.org/abs/2312.04482 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

False vacuum decay rates, more precisely
We develop a method for accurately calculating vacuum decay rates beyond the thin-wall regime in a pure scalar field theory at the one-loop level of the effective action. It accounts for radiative effects resulting from quantum corrections to the classical bounce, including gradient effects stemming from the inhomogeneity of the bounce background. To achieve this, it is necessary to compute not only the functional determinant of the fluctuation operator in the background of the classical bounce…

Vacuum zero point energy of self-interacting quantum fields in dS background
Hassan Firouzjahi, Haidar Sheikhahmadi
https://arxiv.org/abs/2403.10463 https:…

Vacuum zero point energy of self-interacting quantum fields in dS background
We consider self-interacting scalar fields with a conformal coupling in the dS background and study the quantum corrections from bubble loop diagrams. Incorporating the perturbative in-in formalism, we calculate the quantum corrections in the vacuum zero point energy and pressure of self-interacting fields with the potential $V \propto Φ^n $ for even values of $n$. We calculate the equation of state corresponding to these quantum corrections and examine the scaling of the divergent terms in th…

Vacuum zero point energy of self-interacting quantum fields in dS background
Hassan Firouzjahi, Haidar Sheikhahmadi
https://arxiv.org/abs/2403.10463 https:…

Vacuum zero point energy of self-interacting quantum fields in dS background
We consider self-interacting scalar fields with a conformal coupling in the dS background and study the quantum corrections from bubble loop diagrams. Incorporating the perturbative in-in formalism, we calculate the quantum corrections in the vacuum zero point energy and pressure of self-interacting fields with the potential $V \propto Φ^n $ for even values of $n$. We calculate the equation of state corresponding to these quantum corrections and examine the scaling of the divergent terms in th…

This https://arxiv.org/abs/2402.01042 has been replaced.
link: https://scholar.google.com/scholar?q=a

Nonlinear electrodynamics for the vacuum of Dirac materials. Photon magnetic properties and radiation pressures
We investigate the magnetic properties of photons propagating through Dirac materials in the presence of a magnetic field, taking into account both medium and vacuum contributions. The vacuum photon propagation properties are obtained through a second-order expansion of nonlinear Euler-Heisenberg electrodynamics considering Dirac material parameters (effective structure constant, band gap and Fermi velocity, respectively). Total magnetization and effective magnetic moment are obtained. Observab…

The Rise and Fall of the Standard-Model Higgs: Electroweak Vacuum Stability during Kination
Giorgio Laverda, Javier Rubio
https://arxiv.org/abs/2402.06000 …

The Rise and Fall of the Standard-Model Higgs: Electroweak Vacuum Stability during Kination
In this paper we investigate the vacuum stability of the non-minimally coupled Standard-Model Higgs during a phase of kinetic domination following the end of inflation. The non-minimal coupling to curvature stabilises the Higgs fluctuations during inflation while driving them towards the instability scale during kination, when they can classically overcome the potential barrier separating the false electroweak vacuum from the true one at super-Planckian field values. Avoiding the instability of…

This https://arxiv.org/abs/2301.09283 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

New vacuum stability limit from cosmological history
The stability of the electroweak vacuum imposes important constraints on new physics models. Such new physics models may introduce one or more new thermal phases with a lower free energy than that of the electroweak vacuum. In this case, the early universe may stay or have already evolved into one of these deeper vacuum states. We investigate this possibility in detail in the singlet extension of the Standard Model, and delineate the corresponding constraints in its parameter space. We also dis…

This https://arxiv.org/abs/2307.12031 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Light-cone thermodynamics: purification of the Minkowski vacuum
We explicitly express the Minkowski vacuum of a massless scalar field in terms of the particle notion associated with suitable spherical conformal killing fields. These fields are orthogonal to the light wavefronts originating from a sphere with a radius of $r_{H}$ in flat spacetime: a bifurcate conformal killing horizon that exhibits semiclassical features similar to those of black hole horizons and Cauchy horizons of spherically symmetric black holes. Our result highlights the quantum aspects…