Tootfinder

Optimizing Gaussian Process Kernels Using Nested Sampling and ABC Rejection for H(z) Reconstruction
Jia-yan Jiang, Kang Jiao, Tong-Jie Zhang
https://arxiv.org/abs/2506.21238

Optimizing Gaussian Process Kernels Using Nested Sampling and ABC Rejection for H(z) Reconstruction
Recent cosmological observations have achieved high-precision measurements of the Universe's expansion history, prompting the use of nonparametric methods such as Gaussian processes (GP) regression. We apply GP regression for reconstructing the Hubble parameter using CC data, with improved covariance modeling and latest study in CC data. By comparing reconstructions in redshift space $z$ and transformed space $\log(z+1)$ , we evaluate six kernel functions using nested sampling (NS) and approxim…

This https://arxiv.org/abs/2503.09112 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

On the Commuting Problem of Toeplitz Operators on the Harmonic Bergman Space
In this paper, we provide a complete characterization of bounded Toeplitz operators $T_f$ on the harmonic Bergman space of the unit disk, where the symbol $f$ has a polar decomposition truncated above, that commute with $T_{z+\bar{g}}$, for a bounded analytic function $g$.

A pseudometric on $\mathcal{M}(X,\mathscr{A})$ induced by a measure
Amrita Dey
https://arxiv.org/abs/2505.19780 https://arxiv.org/pdf…

A pseudometric on $\mathcal{M}(X,\mathscr{A})$ induced by a measure
For a probability measure space $(X,\mathscr{A},μ)$, we define a pseudometric $δ$ on the ring $\mathcal{M}(X,\mathscr{A})$ of real-valued measurable functions on $X$ as $δ(f,g)=μ(X\setminus Z(f-g))$ and denote the topological space induced by $δ$ as $\mathcal{M}_δ$. We examine several topological properties, such as connectedness, compactness, Lindelöfness, separability and second countability of this pseudometric space. We realise that the space is connected if and only if $μ$ is a non…

An Invariant for Triple-Point-Free Immersed Spheres
Jona Seidel
https://arxiv.org/abs/2506.21130 https://arxiv.org/pdf/2506.21130

An Invariant for Triple-Point-Free Immersed Spheres
We define an invariant of triple-point-free immersions of $2$-spheres into Euclidean $3$-space, taking values in $l^1(\mathbb{Z})$. It remains unchanged under regular homotopies through such immersions. An explicit description of its image shows that the space of triple-point-free immersed spheres has infinitely many regular homotopy classes. Consequently, many pairs of immersed spheres can only be connected by regular homotopies that pass through triple points. We represent the double points o…

Dirichlet-type spaces of the unit bidisc and toral completely hyperexpansive operators
Santu Bera
https://arxiv.org/abs/2506.20143 https://

Dirichlet-type spaces of the unit bidisc and toral completely hyperexpansive operators
We discuss a notion, originally introduced by Aleman in one variable, of Dirichlet-type space $\mathcal D(μ_1,μ_2)$ on the unit bidisc $\mathbb D^2,$ with superharmonic weights related to finite positive Borel measures $μ_1,μ_2$ on $\overline{\mathbb D}.$ The multiplication operators $\mathscr M_{z_1}$ and $\mathscr M_{z_2}$ by the coordinate functions $z_1$ and $z_2,$ respectively, are bounded on $\mathcal D(μ_1,μ_2)$ and the set of polynomials is dense in $\mathcal D(μ_1,μ_2).$ We sho…

Measurements of the z=4-10 X-ray Luminosity Function: the high space density of moderate-luminosity, obscured AGN
C. L. Barlow-Hall, J. Aird
https://arxiv.org/abs/2506.16145

Measurements of the z=4-10 X-ray Luminosity Function: the high space density of moderate-luminosity, obscured AGN
SMBHs are theorised to undergo significant growth in the early Universe, however, the X-ray Luminosity Function (XLF), used as a principal tracer of the SMBH accretion density, lacks observational constraints at z>6, until now. We present new measurements of the z=4-10 XLF at intermediate luminosities, taking advantage of recent deep near-IR imaging from UltraVISTA that enables us to identify galaxies and AGN at high redshifts within which we identify X-ray sources using Chandra COSMOS data. We…

Validity of generalized Gibbs ensemble in a random matrix model with a global $\mathbb{Z}_2$-symmetry
Adway Kumar Das
https://arxiv.org/abs/2506.16176 http…

Validity of generalized Gibbs ensemble in a random matrix model with a global $\mathbb{Z}_2$-symmetry
$\mathbb{Z}_2$ symmetry is ubiquitous in quantum mechanical systems where it drives various phase transitions and emergent physics. To understand the role of $\mathbb{Z}_2$ symmetry in the thermalization of a local observable in a disordered system, we consider random symmetric centrosymmetric (SC) matrices where the exchange symmetry is conserved. Such a conservation law splits the Hilbert space into decoupled subspaces such that the energy spectrum of a SC matrix is a superposition of two pur…

Galactic echoes
Rimpei Chiba, Jupiter Ding, Chris Hamilton, Matthew W. Kunz, Scott Tremaine
https://arxiv.org/abs/2506.16512 https://…

Galactic echoes
Gaia has revealed a variety of substructures in the phase space of stars in the Solar neighborhood, including the vertical `Snail' in $(z,v_z)$ space. Such substructures are often interpreted as the incompletely phase-mixed response of the disc stars to a single perturbation, such as an impulsive encounter with a satellite galaxy. In this paper we consider the possibility that such structures contain manifestations of phase space echoes. First established in plasma physics in the 1960s, echoes …

Checked in at Z-Space. Z in the sunshine

Halfway to the Peak - Ice Absorption Bands at z ≈ 0.5 with JWST MIRI/MRS: #galaxy is much like dust that is closer to us, helping them understand early galactic activity.

Observational Space Unveils Cosmic Expansion's Role in the Hubble Tension
Kang Jiao, Tong-Jie Zhang, Liang Gao
https://arxiv.org/abs/2506.16669 https:/…

Observational Space Unveils Cosmic Expansion's Role in the Hubble Tension
We introduce a geometric embedding method that directly constrains $H_0$ by exploiting the exact kinematic relation $\dot{z} = H_0(1+z) - H(z)$ in a unified observational framework. This approach reconstructs expansion history without requiring specific cosmological models, incorporating both existing Cosmic Chronometer data and forecasted Sandage-Loeb measurements. Through mathematical embedding of observational constraints, we achieve $\sim 1.6\%$ precision in $H_0$ determination, matching cu…

Dynamical sampling, derivatives, and interpolation formulas in the Paley--Wiener space
Iker Gardeazabal-Guti\'errez, Mateus Sousa
https://arxiv.org/abs/2506.16195

Dynamical sampling, derivatives, and interpolation formulas in the Paley--Wiener space
In this paper we present a criteria to obtain interpolations formulas in terms of the sequence $\left(\{T_n(f)(Nm)\}\}_{m\in\mathbb{Z}}\right)_{n=1}^N$, where $f$ are functions whose Fourier transform is supported in $[-1/2,1/2]$, and $T_n$ are certain Fourier multiplier operators. We also discuss applications and also prove that our results recover several classical formulas.

The tangle-valued 1-cocycle for knots
Thomas Fiedler
https://arxiv.org/abs/2506.17738 https://arxiv.org/pdf/2506.17738

The tangle-valued 1-cocycle for knots
This paper contains the strongest and at the same time most calculable knot invariant ever. Let $Θ$ be the topological moduli space of all ordered oriented tangles in 3-space. We construct a non-trivial combinatorial 1-cocycle $\mathbb{L}$ for $Θ$ that takes its values in $H_0(Θ;\mathbb{Z})$. The 1-cocycle $\mathbb{L}$ has a very nice property, called the {\em scan-property}: if we slide a tangle $T$ over or under a given crossing $c$ of a fixed tangle $T'$, then the value of $\mathbb{L}$ …

lmao "the dork web" https://kolektiva.social/@franklinlopez/114672562818500830

Cohomology of hypersurfaces of weighted projective space and the intersection form on $H^2$
Anna-Maria Raukh
https://arxiv.org/abs/2506.04094 https://

Cohomology of hypersurfaces of weighted projective space and the intersection form on $H^2$
Given a hypersurface $i \colon X \hookrightarrow \widetilde{P}^n$ in a weighted projective space, we compute the intersection form on the second cohomology $H^2(X, \mathbb{Z})^{\otimes n-1} \to \mathbb{Z}$ for the purpose of identifying Fano manifolds obtained from smoothing singular Fanos. In the process, we describe the integer cohomology groups $H^k(X, \mathbb{Z})$ for $k

Symbolic Generation and Modular Embedding of High-Quality abc-Triples
Michael A. Idowu
https://arxiv.org/abs/2506.10039 https://arxiv…

Symbolic Generation and Modular Embedding of High-Quality abc-Triples
We present a symbolic identity for generating integer triples $(a, b, c)$ satisfying $a + b = c$, inspired by structural features of the \emph{abc conjecture}. The construction uses powers of $2$ and $3$ in combination with modular inversion in $\mathbb{Z}/3^p\mathbb{Z}$, leading to a parametric identity with residue constraints that yield abc-triples exhibiting low radical values. Through affine transformations, these symbolic triples are embedded into a broader space of high-quality examples,…

Orbit dimensions in linear and Gaussian quantum optics
Eliott Z. Mamon
https://arxiv.org/abs/2506.07995 https://arxiv.org/pdf/2506.07…

Orbit dimensions in linear and Gaussian quantum optics
In sub-universal quantum platforms such as linear or Gaussian quantum optics, quantum states can behave as different resources, in regard to the extent of their accessible state space (called their orbit) under the action of the restricted unitary group. We propose to study the dimension of a quantum state's orbit (as a manifold in the Hilbert space), a simple yet nontrivial topological property that can quantify "how many" states it can reach. As natural invariants under the group, these struc…

Simulation of parametrized cardiac electrophysiology in three dimensions using physics-informed neural networks
Roshan Antony Gomez, Julien St\"ocker, Bar{\i}\c{s} Cans{\i}z, Michael Kaliske
https://arxiv.org/abs/2506.15405

Simulation of parametrized cardiac electrophysiology in three dimensions using physics-informed neural networks
Physics-informed neural networks (PINNs) are extensively used to represent various physical systems across multiple scientific domains. The same can be said for cardiac electrophysiology, wherein fully-connected neural networks (FCNNs) have been employed to predict the evolution of an action potential in a 2D space following the two-parameter phenomenological Aliev-Panfilov (AP) model. In this paper, the training behaviour of PINNs is investigated to determine optimal hyperparameters to predict…

Euclid: The potential of slitless infrared spectroscopy: A z=5.4 quasar and new ultracool dwarfs
E. Ba\~nados, V. Le Brun, S. Belladitta, I. Momcheva, D. Stern, J. Wolf, M. Ezziati, D. J. Mortlock, A. Humphrey, R. L. Smart, S. L. Casewell, A. P\'erez-Garrido, B. Goldman, E. L. Mart\'in, A. Mohandasan, C. Reyl\'e, C. Dominguez-Tagle, Y. Copin, E. Lusso, Y. Matsuoka, K. McCarthy, F. Ricci, H. -W. Rix, H. J. A. Rottgering, J. -T. Schindler, J. R. Weaver, A. Allaoui, T. Bedrine…

Euclid: The potential of slitless infrared spectroscopy: A z=5.4 quasar and new ultracool dwarfs
We demonstrate the potential of Euclid's slitless spectroscopy to discover high-redshift (z>5) quasars and their main photometric contaminant, ultracool dwarfs. Sensitive infrared spectroscopy from space is able to efficiently identify both populations, as demonstrated by Euclid Near-Infrared Spectrometer and Photometer Red Grism (NISP RGE) spectra of the newly discovered z=5.404 quasar EUCL J181530.01+652054.0, as well as several ultracool dwarfs in the Euclid Deep Field North and the Euclid E…

The dynamics of background evolution and structure formation in phase space: a semi-cosmographic reconstruction
Pankaj Chavan, Tapomoy Guha Sarkar, Anjan A Sen
https://arxiv.org/abs/2506.14275

The dynamics of background evolution and structure formation in phase space: a semi-cosmographic reconstruction
The Baryon Acoustic Oscillation (BAO) feature, imprinted in the transverse and radial clustering of dark matter tracers, enables the simultaneous measurement of the angular diameter distance $D_A(z)$ and the Hubble parameter $H(z)$ at a given redshift. Further, measuring the redshift space anisotropy (RSD) allows us to measure the combination $f_8\equiv fσ_8(z)$. Motivated by this, we simultaneously study the dynamics of background evolution and structure formation in an abstract phase space o…

Dense Phenomena for Ergodic Schr\"odinger Operators: I. Spectrum, Integrated Density of States, and Lyapunov Exponent
Artur Avila (Universit\"at Z\"urich,IMPA), David Damanik (Rice University)
https://arxiv.org/abs/2506.14259

Dense Phenomena for Ergodic Schrödinger Operators: I. Spectrum, Integrated Density of States, and Lyapunov Exponent
We consider Schrödinger operators in $\ell^2(\Z)$ whose potentials are defined via continuous sampling along the orbits of a homeomorphism on a compact metric space. We show that for each non-atomic ergodic measure $μ$, there is a dense set of sampling functions such that the associated almost sure spectrum has finitely many gaps, the integrated density is smooth, and the Lyapunov exponent is smooth and positive. As a byproduct we answer a question of Walters about the existence of non-unifor…

Rieffel projections and 2-by-2 matrices
Olivier Isely, Alain Valette
https://arxiv.org/abs/2506.12640 https://arxiv.org/pdf/2506.1264…

Rieffel projections and 2-by-2 matrices
For a compact space $Y$, we view $C(Y\times S^1)$ as the crossed product $C(Y)\rtimes\mathbb{Z}$, with $\mathbb{Z}$ acting trivially. This allows us to study Rieffel projections in $M_2(C(Y\times S^1))$: we characterize them and compute their image under the projection $\partial_0:K_0(C(Y\times S^1))\rightarrow K_1(C(Y))$. We provide a new Rieffel projection in $M_2(C(\mathbb{T}^2))$, different from Loring's one, and involving only trigonometric polynomials plus the square root of $2-e^{2πiθ}…

A Note on the Reliability of Goal-Oriented Error Estimates for Galerkin Finite Element Methods with Nonlinear Functionals
Brian N. Granzow, Stephen D. Bond, D. Thomas Seidl, Bernhard Endtmayer
https://arxiv.org/abs/2506.09913

A Note on the Reliability of Goal-Oriented Error Estimates for Galerkin Finite Element Methods with Nonlinear Functionals
We consider estimating the discretization error in a nonlinear functional $J(u)$ in the setting of an abstract variational problem: find $u \in \mathcal{V}$ such that $B(u,φ) = L(φ) \; \forall φ\in \mathcal{V}$, as approximated by a Galerkin finite element method. Here, $\mathcal{V}$ is a Hilbert space, $B(\cdot,\cdot)$ is a bilinear form, and $L(\cdot)$ is a linear functional. We consider well-known error estimates $η$ of the form $J(u) - J(u_h) \approx η= L(z) - B(u_h, z)$, where $u_h$ d…

A unified neural background-error covariance model for midlatitude and tropical atmospheric data assimilation
Bo\v{s}tjan Melinc, Uro\v{s} Perkan, \v{Z}iga Zaplotnik
https://arxiv.org/abs/2506.11968

A unified neural background-error covariance model for midlatitude and tropical atmospheric data assimilation
Estimating background-error covariances remains a core challenge in variational data assimilation (DA). Operational systems typically approximate these covariances by transformations that separate geostrophically balanced components from unbalanced inertio-gravity modes - an approach well-suited for the midlatitudes but less applicable in the tropics, where different physical balances prevail. This study estimates background-error covariances in a reduced-dimension latent space learned by a neu…

Non-oscillatory gravitational quasinormal modes of Reissner-Nordstr\"om-de Sitter spacetime
Z. Stuchl\'ik, A. Zhidenko
https://arxiv.org/abs/2506.09829

Non-oscillatory gravitational quasinormal modes of Reissner-Nordström-de Sitter spacetime
Proper oscillation frequencies of black holes (quasinormal modes) of asymptotically de Sitter black holes were extensively studied, yet the non-oscillatory (purely imaginary) branch of modes of gravitational perturbations of the four-dimensional Reissner-Nordström-de Sitter solution was omitted in the literature. This branch of modes appears as deformations of the modes of empty de Sitter space. Here we find accurate numerical values of this branch of quasinormal modes and show that they are r…

Boundedness of average rank of elliptic curves ordered by the coefficients
Fatemehzahra Janbazi
https://arxiv.org/abs/2506.07089 https://

Boundedness of average rank of elliptic curves ordered by the coefficients
We study the average rank of elliptic curves $E_{A,B} : y^2 = x^3 + Ax + B$ over $\mathbb{Q}$, ordered by the height function $h(E_{A,B}) := \text{max}(|A|, |B|)$. Understanding this average rank requires estimating the number of irreducible integral binary quartic forms under the action of $\mathrm{GL}_2(\mathbb{Z})$, where the invariants $I$ and $J$ are bounded by $X$. A key challenge in this estimation arises from working within regions of the quartic form space that expa…

Signatures of BH seeding on the $\mathrm{M_{\displaystyle \bullet}}-\sigma$ relation: Predictions from the BRAHMA simulations
Jonathan Kho, Aklant K. Bhowmick, Paul Torrey, Alex M. Garcia, Niusha Ahvazi, Laura Blecha, Mark Vogelsberger
https://arxiv.org/abs/2506.17476

Signatures of BH seeding on the $\mathrm{M_{\displaystyle \bullet}}-σ$ relation: Predictions from the BRAHMA simulations
The James Webb Space Telescope (JWST) has identified a large population of supermassive ($10^6$-$10^8~\mathrm{M}_\odot$) black holes (BHs) in the early universe ($z \sim 4$-$7$). Current measurements suggest that many of these BHs exhibit higher BH-to-stellar mass ratios than local populations, opening a new window into the earliest stages of BH-galaxy coevolution and offering the potential to place tight constraints on BH seeding and growth in the early universe. In this work, we use the BRAHM…

Initial Characterization of Stellar Photometry of Roman images from the OpenUniverse Simulations
Lauren Aldoroty, Daniel Scolnic, Arun Kannawadi, Rob Knop, Benjamin Rose, Rebekah Hounsell, Michael Troxel
https://arxiv.org/abs/2506.04332

Initial Characterization of Stellar Photometry of Roman images from the OpenUniverse Simulations
NASA's Nancy Grace Roman Space Telescope (Roman) will provide an opportunity to study dark energy with unprecedented precision and accuracy using several techniques, including measurements of high-$z$ Type Ia Supernovae (SNe Ia, $z \lesssim 3.0$) via the High-Latitude Time Domain Survey (HLTDS). In this work, we do an initial "benchmark" characterization of the photometric repeatability of stellar fluxes, which must be below $1\%$ when sky noise is subdominant in order xto enable a number of ca…

This https://arxiv.org/abs/2506.04564 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Cauchy Integral, Fractional Sobolev Spaces and Chord-Arc Curves
Let $Γ$ be a bounded Jordan curve and $Ω_i,Ω_e$ its two complementary components. For $s\in(0,1)$ we define $\mathcal{H}^s(Γ)$ as the set of functions $f:Γ\to \mathbb C$ having harmonic extension $u$ in $Ω_i\cup Ω_e$ such that $$ \iint_{Ω_i\cup Ω_e} |\nabla u(z)|^2 d(z,Γ)^{1-2s} dxdy<+\infty.$$ If $Γ$ is further assumed to be rectifiable we define $H^s(Γ)$ as the space of measurable functions $f:Γ\to \mathbb C$ such that $$\iint_{Γ\times Γ}\frac{|f(z)-f(ζ)|^2…

Irreducible modules over the universal central extension of the planar Galilean conformal algebra
Dongfang Gao
https://arxiv.org/abs/2506.10196 https://

Irreducible modules over the universal central extension of the planar Galilean conformal algebra
In this paper, we study the representation theory of the universal central extension $\mathcal{G}$ of the infinite-dimensional Galilean conformal algebra, introduced by Bagchi-Gopakumar, in $(2+1)$ dimensional space-time, which was named the planar Galilean conformal algebra by Aizawa. More precisely, we construct a family of Whittaker modules $W_{ψ_{m,n}}$ over $\mathcal{G}$ while the necessary and sufficient conditions for these modules to be irreducible are given when $m\in\mathbb{Z}_+, n\i…

This https://arxiv.org/abs/2412.04352 has been replaced.
initial toot: https://mastoxiv.page/@a…

Emergent Weyl-like points in periodically modulated systems and Floquet engineering
We investigate a three-dimensional (3D) topological phase resembling a Weyl semimetal, modulated by a periodic potential and engineered through Floquet dynamics. This system is constructed by stacking two-dimensional Chern insulators and hosts Weyl-like points defined in the parameter space $(k_x, k_y, z)$, distinct from conventional Weyl points in momentum space $(k_x, k_y, k_z)$. The Weyl-semimetal-like phase exhibits characteristics akin to those of Weyl semimetals, including linear dispersi…

Stable invariant manifold for generalized ODEs with applications to measure differential equations
Lu Weijie, Piccione Paolo, Xia Yonghui
https://arxiv.org/abs/2506.02874

Stable invariant manifold for generalized ODEs with applications to measure differential equations
This paper establishes the stable invariant manifold for a new kind of differential equations defined by Kurzweil integral, so-called {\em generalized ODEs} on a Banach space. The nonlinear generalized ODEs are formulated as $$ \frac{dz}{dτ}=D[Λ(t)z+F(z,t)], $$ where $Λ(t)$ is a bounded linear operator on a Banach space $\mathscr{Z}$ and $F(z,t)$ is a nonlinear Kurzweil integrable function on $\mathscr{Z}$. The letter $D$ represents that generalized ODEs are defined via its solution, and $\f…

The @… crew are doing a group order of meshtastic wireless devices.
We've selected the Wismesh Pocket v2 plus a small card sized sensor / buzzer. These connect up to 7 hops and we'll be installing 2 solar powered repeaters in Gastown & Mt Pleasant (as well as direct between any two devices)
Fill out the form …

JWST Reveals a Likely Jellyfish Galaxy at z=1.156
Ian D. Roberts, Michael L. Balogh, Visal Sok, Adam Muzzin, Michael J. Hudson, Pascale Jablonka
https://arxiv.org/abs/2506.14117

JWST Reveals a Likely Jellyfish Galaxy at z=1.156
We report the discovery of COSMOS2020-635829 as a likely jellyfish galaxy undergoing to ram pressure stripping in a (proto)cluster at $z > 1$. High-resolution imaging from the James Webb Space Telescope reveals a symmetric stellar disk coupled to a unilateral tail of star-forming knots to the south. We show that these extra-planar continuum sources are embedded within an ionized gas tail that is kinematically connected to the disk of COSMOS2020-635829. Likely representing the highest-redshift d…

This https://arxiv.org/abs/1804.08452 has been replaced.
link: https://scholar.google.com/scholar?q=a

Two closed geodesics on compact bumpy Finsler manifolds
In this paper, we prove there are at least two closed geodesics on any compact bumpy Finsler $n$-manifold with finite fundamental group and $n\ge 2$. Thus generically there are at least two closed geodesics on compact Finsler manifolds with finite fundamental group. Furthermore, there are at least two closed geodesics on any compact Finsler $2$-manifold, and this lower bound is achieved by the Katok 2-sphere $(S^2, F)$ and 2-real projective space $(S^2/\Z_2, F)$, cf. \cite{Kat}.

Testing Coasting Cosmologies with Large-Scale Structure Growth
D\'avid A. K\"odm\"on, P\'eter Raffai
https://arxiv.org/abs/2506.11826 htt…

Testing Coasting Cosmologies with Large-Scale Structure Growth
We derive analytical expressions for the growth factor, $D(z)$, and density-weighted growth rate, $fσ_8(z)$, for coasting cosmologies, in which the scale factor is a linear function of time. We fit the latter to data from redshift space distortion measurements in the redshift range $z<2$ using the \texttt{dynesty} implementation of a nested sampling algorithm. In total, four models are tested: three coasting models with curvature parameters ${k=\{-1, 0, +1\}}$ in $H^2_0c^{-2}$ units, as well a…

The DORCHA suite: nature, nurture, and the phase space distribution of the Milky Way's high redshift progenitors today
Sreedhar Balu, Chris Power, Kris Walker, J. Stuart B. Wyithe
https://arxiv.org/abs/2506.14016

The DORCHA suite: nature, nurture, and the phase space distribution of the Milky Way's high redshift progenitors today
Where in the present-day Milky Way should we search for the remnants of its earliest stars? We address this question using the DORCHA (Gaelic for Dark; DUR-uh-khuh) suite: a set of 25 high-resolution, dark-matter-only cosmological zoom-in simulations of Milky Way analogue (MWA) haloes evolved to $z=0$. Of these, 15 are isolated and the rest are in pairs, similar to the MW and M31. By identifying and tagging the most bound material in high-redshift ($z\geq5$) progenitor haloes -- those likely to…

This https://arxiv.org/abs/2505.23488 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Moduli spaces of twisted equivariant G-bundles over a curve
Let $X$ be a compact Riemann surface, $Γ$ a finite group of automorphisms of $X$ and $G$ a connected reductive complex Lie group with center $Z$. If we equip this data with a homomorphism $θ:Γ\to\text{Aut}(G)$ and a 2-cocycle $c:Γ\timesΓ\to Z$, there is a notion of $(θ,c)$-twisted $Γ$-equivariant $G$-bundle over $X$. The aim of this paper is to construct a coarse moduli space of isomorphism classes of polystable $(θ,c)$-twisted equivariant $G$-bundles over $X$, according to the definiti…

Computing Nonlinear Power Spectra Across Dynamical Dark Energy Model Space with Neural ODEs
Peter L. Taylor
https://arxiv.org/abs/2506.09128 https://

Computing Nonlinear Power Spectra Across Dynamical Dark Energy Model Space with Neural ODEs
I show how to compute the nonlinear power spectrum across the entire $w(z)$ dynamical dark energy model space. Using synthetic $Λ$CDM data, I train a neural ordinary differential equation (ODE) to infer the evolution of the nonlinear matter power spectrum as a function of the background expansion and mean matter density across $\sim$$9 {\rm \ Gyr}$ of cosmic evolution. After training, the model generalises to {\it any} dynamical dark energy model parameterised by $w(z)$. With little optimisati…

Cauchy Integral, Fractional Sobolev Spaces and Chord-Arc Curves
Huaying Wei, Michel Zinsmeister
https://arxiv.org/abs/2506.04564 https://

Cauchy Integral, Fractional Sobolev Spaces and Chord-Arc Curves
Let $Γ$ be a bounded Jordan curve and $Ω_i,Ω_e$ its two complementary components. For $s\in(0,1)$ we define $\mathcal{H}^s(Γ)$ as the set of functions $f:Γ\to \mathbb C$ having harmonic extension $u$ in $Ω_i\cup Ω_e$ such that $$ \iint_{Ω_i\cup Ω_e} |\nabla u(z)|^2 d(z,Γ)^{1-2s} dxdy<+\infty.$$ If $Γ$ is further assumed to be rectifiable we define $H^s(Γ)$ as the space of measurable functions $f:Γ\to \mathbb C$ such that $$\iint_{Γ\times Γ}\frac{|f(z)-f(ζ)|^2…

Homology manifolds and homogeneous compacta
Vesko Valov
https://arxiv.org/abs/2505.07196 https://arxiv.org/pdf/2505.07196

Homology manifolds and homogeneous compacta
A non-trivial separable metric space $X$ is called an almost homology $n$-manifold if the homology groups $H_k(X,X\backslash\{x\},\mathbb Z)$ are trivial for all $x\in X$ and all $k=0,1,..,n-1$. We provide a necessary and sufficient condition locally compact homogeneous $ANR$-spaces or strongly locally homogeneous $ANR$-spaces to be almost homology $n$-manifolds.

This https://arxiv.org/abs/2505.20384 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Generalized Hall Conductivities in Local Commuting Projector Models: Generalized Symmetries and Protected Surface Modes
Hall conductivities are important characterizations of phases of matter. It is known that nonzero Hall conductivities are difficult to realize in local commuting projector lattice models due to no-go theorems in (2+1)D. In this work we construct local commuting projector models in (2+1)D and (3+1)D with nonzero generalized Hall conductivities for ordinary and higher-form continuous symmetries on tensor product Hilbert space of finite local dimension. The model is given by a standard $\mathbb{Z}…

Automated Polarization Basis Adjustment and Security Monitoring in Quantum Communication via Coincidence Entropies
Tom\'a\v{s} Nov\'ak, Carlos Guerra-Y\'anez, Mat\v{e}j Holubi\v{c}ka, Josef Vojt\v{e}ch, Josef Bla\v{z}ej
https://arxiv.org/abs/2505.24071

Automated Polarization Basis Adjustment and Security Monitoring in Quantum Communication via Coincidence Entropies
Polarization-sensitive receivers for single photons are of crucial importance in various applications within the fields of quantum communication and quantum sensing, and are more commonly implemented in free-space optics rather than in optical fibers. This is primarily due to the unpredictable and varying birefringence in single-mode optical fibers. We present a method for birefringence compensation in an all-fiber detection setup that relies solely on coincidence measurements of a polarization…

SPECULOOS: five years hunting terrestrial planets around ultra-cool dwarfs
Sebasti\'an Z\'u\~niga-Fern\'andez (Astrobiology Research Unit, Universit\'e de Li\`ege, Li\`ege, Belgium), Michael Gillon (Astrobiology Research Unit, Universit\'e de Li\`ege, Li\`ege, Belgium), SPECULOOS consortium
https://arxiv.org/…

SPECULOOS: five years hunting terrestrial planets around ultra-cool dwarfs
The SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) project aims to detect temperate terrestrial planets transiting nearby ultracool dwarfs, including late M-dwarf stars and brown dwarfs, which are well-suited for atmospheric characterization using the James Webb Space Telescope (JWST) and upcoming giant telescopes like the European Extremely Large Telescope (ELT). Led by the University of Liège, SPECULOOS is conducted in partnership with the University of Cambridge, the Un…

This https://arxiv.org/abs/2407.08438 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Symmetries of power-free integers in number fields and their shift spaces
We describe the group of $\mathbb Z$-linear automorphisms of the ring of integers of a number field $K$ that preserve the set $V_{K,k}$ of $k$th power-free integers: every such map is the composition of a field automorphism and the multiplication by a unit. We show that those maps together with translations generate the extended symmetry group of the shift space $\mathbb D_{K,k}$ associated to $V_{K,k}$. Moreover, we show that no two such dynamical systems $\mathbb D_{K,k}$ and $\mathbb D_{L,…

Prospects for the Detection of High-Redshift Gamma-Ray Bursts in the Era of EP and SVOM
Jun-Jie Wei, Xue-Feng Wu
https://arxiv.org/abs/2506.04709 https://

Prospects for the Detection of High-Redshift Gamma-Ray Bursts in the Era of EP and SVOM
Gamma-ray bursts (GRBs) are a promising probe of the high-redshift Universe, but their detection remains observationally challenging. In this work, we explore the detectability of high-$z$ GRBs by the Wide-field X-ray Telescope (WXT) aboard the Einstein Probe (\emph{EP}) and the coded-mask gamma-ray imager (ECLAIRs) aboard the Space-based multi-band astronomical Variable Objects Monitor (\emph{SVOM}). Using a population synthesis model calibrated to $Swift$ GRB observations, we develop a tool t…

This https://arxiv.org/abs/2406.10189 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Topological rigidity of small RCD(K,N) spaces with maximal rank
For a polycyclic group $Λ$, $\text{rank} ( Λ)$ is defined as the number of $\mathbb{Z}$ factors in a polycyclic decomposition of $Λ$. For a finitely generated group $G$, $\text{rank} (G)$ is defined as the infimum of $ \text{rank} (Λ)$ among finite index polycyclic subgroups $Λ\leq G$. For a compact $\text{RCD} (K,N)$ space $(X,\mathsf{d}, \mathfrak{m})$ with $\text{diam} (X) \leq \varepsilon (K,N)$, the rank of $π_1(X)$ is at most $N$. We show that in case of equality, $X$ is homeomorphi…

Embedding theorems for Bergman-Zygmund spaces induced by doubling weights
Atte Pennanen
https://arxiv.org/abs/2505.23211 https://arxi…

Embedding theorems for Bergman-Zygmund spaces induced by doubling weights
Let $0

Moduli spaces of twisted equivariant G-bundles over a curve
Guillermo Barajas
https://arxiv.org/abs/2505.23488 https://arxiv.org/pdf/…

Moduli spaces of twisted equivariant G-bundles over a curve
Let $X$ be a compact Riemann surface, $Γ$ a finite group of automorphisms of $X$ and $G$ a connected reductive complex Lie group with center $Z$. If we equip this data with a homomorphism $θ:Γ\to\text{Aut}(G)$ and a 2-cocycle $c:Γ\timesΓ\to Z$, there is a notion of $(θ,c)$-twisted $Γ$-equivariant $G$-bundle over $X$. The aim of this paper is to construct a coarse moduli space of isomorphism classes of polystable $(θ,c)$-twisted equivariant $G$-bundles over $X$, according to the definiti…

Floquet M\"obius topological insulators
Longwen Zhou, Fan Zhang, Jiaxin Pan
https://arxiv.org/abs/2506.01401 https://arxiv.org/p…

Floquet Möbius topological insulators
Möbius topological insulators hold twofold-degenerated dispersive edge bands with Möbius twists in momentum space, which are protected by the combination of chiral and ${\mathbb Z}_2$-projective translational symmetries. In this work, we reveal a unique type of Möbius topological insulator, whose edge bands could twist around the quasienergy $π$ of a periodically driven system and are thus of Floquet origin. By applying time-periodic quenches to an experimentally realized Möbius insulator …

Brightest Group Galaxies IV: Probing Size--Mass Relation and Morphological Quenching in COSMOS-Web from $z = 3.7$
Ghassem Gozaliasl, Lilan Yang, Greta Toni, Fatemeh Abedini, Rafael C. Arango-Toro, Arif Babul, Caitlin M. Casey, Nima Chartap, Nicole E. Drakos, Andreas L. Faisst, Alexis Finoguenov, Maximilien Franco, Gavin Leroy, G\"unther Hasinger, Hossein Hatamnia, Olivier Ilbert, Shuowen Jin, Darshan Kakkad, Atousa Kalantari, Jeyhan S. Kartaltepe, Ali Ahmad Khostovan, Anton M. Koe…

Brightest Group Galaxies IV: Probing Size--Mass Relation and Morphological Quenching in COSMOS-Web from $z = 3.7$
We present a comprehensive study of the structural evolution of Brightest Group Galaxies (BGGs) from redshift $z \simeq 0.08$ to $z = 3.7$ using the \textit{James Webb Space Telescope}'s 255h COSMOS-Web program. This survey provides deep NIRCam imaging in four filters (F115W, F150W, F277W, F444W) across $\sim 0.54~\mathrm{deg}^2$ and MIRI coverage in $\sim 0.2~\mathrm{deg}^2$ of the COSMOS field. High-resolution NIRCam imaging enables robust size and morphological measurements, while multiwavel…

Clumpiness of galaxies revealed in the near-infrared with COSMOS-Web
Wilfried Mercier, Boris Sindhu Kalita, Marko Shuntov, Rafael C. Arango-Toro, Olivier Ilbert, Laurence Tresse, Yohan Dubois, Clotilde Laigle, Hossein Hatamnia, Nicolas McMahon, Andreas Faisst, Isa Cox, Maxime Trebitsch, Leo Michel-Dansac, Si-Yue Yu, Michaela Hirschmann, Marc Huertas-Company, Arianna Long, Anton Koekemoer, Gr\'egoire Aufort, Joseph Lewis, Ghassem Gozaliasl, R. Michael Rich, Jason Rhodes, Henry Joy M…

Clumpiness of galaxies revealed in the near-infrared with COSMOS-Web
Clumps in the rest-frame UV emission of galaxies have been observed for decades. Since the launch of the James Webb Space Telescope (JWST), a large population is detected in the rest-frame near-infrared (NIR), raising questions about their formation mechanism. We investigate the presence and properties of NIR over-densities (hereafter substructures) in star-forming and quiescent galaxies at 1 < z < 4 to understand their link to the evolution of their host galaxy. We identify substructures in JW…

This https://arxiv.org/abs/2505.20656 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

A joint analysis of 3D clustering and galaxy \times CMB-lensing cross-correlations with DESI DR1 galaxies
The spectroscopic data from DESI Data Release 1 (DR1) galaxies enables the analysis of 3D clustering by fitting galaxy power spectra and reconstructed correlation functions in redshift space. Given low measurements of the amplitude of structure from cosmic shear at $z\sim1$, redshift space distortions (RSD) + Baryon Acoustic Oscillation (BAO) signals from DESI galaxies combined with weak lensing can break degeneracies and provide a tight alternative constraint on the $z\sim1$ amplitude of struc…

The near infrared airglow continuum conundrum. Constraints for ground-based faint object spectroscopy
J. K. M. Viuho (Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Jagtvej 155A, DK-2200, Copenhagen N, Denmark, Nordic Optical Telescope, Rambla Jose Ana Fernandez Perez 7, ES-38711 Brena Baja, Spain, Department of Physics and Astronomy, Aarhus University, Munkegade 120, DK-8000 Aarhus C, Denmark), J. P. U. Fynbo (Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Jagtvej 155A, DK-2200, Copenhagen N, Denmark), M. I. Andersen (Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen, Jagtvej 155A, DK-2200, Copenhagen N, Denmark)
#toXiv_bot_toot

This https://arxiv.org/abs/2506.04031 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Brightest Group Galaxies IV: Probing Size--Mass Relation and Morphological Quenching in COSMOS-Web from $z = 3.7$
We present a comprehensive study of the structural evolution of Brightest Group Galaxies (BGGs) from redshift $z \simeq 0.08$ to $z = 3.7$ using the \textit{James Webb Space Telescope}'s 255h COSMOS-Web program. This survey provides deep NIRCam imaging in four filters (F115W, F150W, F277W, F444W) across $\sim 0.54~\mathrm{deg}^2$ and MIRI coverage in $\sim 0.2~\mathrm{deg}^2$ of the COSMOS field. High-resolution NIRCam imaging enables robust size and morphological measurements, while multiwavel…

The properties of primordially-seeded black holes and their hosts in the first billion years: implications for JWST
Pratika Dayal, Roberto maiolino
https://arxiv.org/abs/2506.08116

The properties of primordially-seeded black holes and their hosts in the first billion years: implications for JWST
James Webb Space Telescope (JWST) observations have opened a tantalising new window onto possible black holes as early as redshifts of $z \sim 10.4$. These show a number of puzzling properties including unexpectedly massive black holes in place by $z \sim 10$ and inexplicably high black hole-to-stellar mass ratios of $M_{\rm BH}/M_*\geq 0.1$. These pose a serious challenge for "astrophysical" seeding and growth models that we aim to explain with ``cosmological" primordial black holes (PBHs) in …

Impact of redshift distribution uncertainties on Lyman-break galaxy cosmological parameter inference
Francesco Petri, Boris Leistedt, Daniel J. Mortlock, Joel Leja, Stephen Thorp, Justin Alsing, Hiranya V. Peiris, Sinan Deger
https://arxiv.org/abs/2506.06475

Impact of redshift distribution uncertainties on Lyman-break galaxy cosmological parameter inference
A significant number of Lyman-break galaxies (LBGs) with redshifts 3 < z < 5 are expected to be observed by the upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). This will enable us to probe the universe at higher redshifts than is currently possible with cosmological galaxy clustering and weak lensing surveys. However, accurate inference of cosmological parameters requires precise knowledge of the redshift distributions of selected galaxies, where the number of faint o…

Phase-space distortion as a key to unraveling galactic bar buckling
Viktor D. Zozulia, Natalia Ya. Sotnikova, Anton A. Smirnov
https://arxiv.org/abs/2506.00631

Phase-space distortion as a key to unraveling galactic bar buckling
For the first time, we investigate the resonant structure of $N$-body galactic bar at the stage of buckling using action-angle variables. We studied the evolution of vertical actions ($J_z$) and angles associated with vertical resonance ($θ_\mathrm{res}=θ_z - θ_R$) for all orbits in the bar. For this purpose, we divide the orbits into types according to the behavior (libration or circulation) of their resonant angle with respect to fixed points $θ_\mathrm{res}=0$ and $π$ (vertical resonanc…

An Ultra-Faint, Chemically Primitive Galaxy Forming at the Epoch of Reionization
Kimihiko Nakajima, Masami Ouchi, Yuichi Harikane, Eros Vanzella, Yoshiaki Ono, Yuki Isobe, Moka Nishigaki, Takuji Tsujimoto, Fumitaka Nakamura, Yi Xu, Hiroya Umeda, Yechi Zhang
https://arxiv.org/abs/2506.11846…

An Ultra-Faint, Chemically Primitive Galaxy Forming at the Epoch of Reionization
The formation of the first stars and galaxies marked the onset of cosmic structure and chemical enrichment, yet direct observations of such primordial systems remain elusive. Here we present James Webb Space Telescope spectroscopic observations of LAP1-B, an ultra-faint galaxy at redshift z_{spec}=6.625 +/-0.001, corresponding to a cosmic age of 800 million years after the Big Bang, strongly magnified by gravitational lensing. LAP1-B exhibits a gas-phase oxygen abundance of (4.2 +/- 1.8) x 10^{…

Formation of the Two-Armed Phase Spiral from Multiple External Perturbations
Junxian Lin, Zhao-Yu Li, Rui Guo, Jason A. S. Hunt, Teresa Antoja, Chengye Cao
https://arxiv.org/abs/2506.04705

Formation of the Two-Armed Phase Spiral from Multiple External Perturbations
Recent studies using the Gaia DR3 data have revealed a two-armed phase spiral in the $Z-V_Z$ phase space in the inner disk. In this study, we present new features of the two-armed phase spiral revealed by the Gaia Data and a new mechanism to explain such features with multiple external perturbations. By segmenting the Gaia DR3 RVS catalog based on $J_ϕ$ (or $R_{g}$) and $θ_ϕ$, we confirm the existence of the clear two-armed phase spiral in the inner disk. Moreover, we identify a different tw…

JWST Insights into Narrow-line Little Red Dots
Zijian Zhang, Linhua Jiang, Weiyang Liu, Luis C. Ho, Kohei Inayoshi
https://arxiv.org/abs/2506.04350 https:/…

JWST Insights into Narrow-line Little Red Dots
James Webb Space Telescope (JWST) has revealed a population of red and compact objects with a unique V-shape SED at z >= 4 known as Little Red Dots (LRDs). Most of the LRDs with existing spectral observations exhibit broad Balmer lines and are thus likely to host active galactic nuclei (AGNs). Here we present a study of LRDs with no broad H-alpha component. Our sample consists of five LRDs at z~5 with H-alpha line widths of about 250 km/s. They are selected from 32 LRDs that have NIRSpec high- …

This https://arxiv.org/abs/2506.00631 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Phase-space distortion as a key to unraveling galactic bar buckling
For the first time, we investigate the resonant structure of $N$-body galactic bar at the stage of buckling using action-angle variables. We studied the evolution of vertical actions ($J_z$) and angles associated with vertical resonance ($θ_\mathrm{res}=θ_z - θ_R$) for all orbits in the bar. For this purpose, we divide the orbits into types according to the behavior (libration or circulation) of their resonant angle with respect to fixed points $θ_\mathrm{res}=0$ and $π$ (vertical resonanc…

Bar-driven dispersal of Galactic substructure
Adam M. Dillamore, Jason L. Sanders
https://arxiv.org/abs/2506.09117 https://arxiv.org/…

Bar-driven dispersal of Galactic substructure
Galactic archaeologists often assume that integrals of motion (IoMs) such as $L_z$ and $E$ are conserved, so substructure remains frozen in IoM space over many Gyr. However, this is not true in the Milky Way due in part to its rotating bar. In this study we quantify the effects of the bar on the dynamics of substructure. We employ three different theoretical models: an analytical toy model; a set of test particle simulations with steady and slowing bars; and a cosmological zoom-in simulation of…

This https://arxiv.org/abs/2505.04825 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

SHELLQs. Bridging the gap: JWST unveils obscured quasars in the most luminous galaxies at z > 6
The unprecedented sensitivity of the James Webb Space Telescope (JWST) has uncovered a surprisingly abundant population of mildly obscured, low-luminosity active galactic nuclei (AGNs) in the epoch of reionization (EoR). However, the link between these objects and classical unobscured quasars remains a mystery. Here we report the discovery of obscured quasars hosted by the most luminous galaxies at $z > 6$, possibly bridging the gap between the two AGN populations. The 13 objects presented here…

RIDEN pilot survey: broad-band selection of candidate quasars with extended Lyman-$\alpha$ nebulae using CLAUDS-HSC-SSP-DUNES$^2$ joint data
Rhythm Shimakawa, Satoshi Kikuta, Haruka Kusakabe, Marcin Sawicki, Yongming Liang, Rieko Momose, Stephen Gwyn, Guillaume Desprez
https://arxiv.org/abs/2506.04570

RIDEN pilot survey: broad-band selection of candidate quasars with extended Lyman-$α$ nebulae using CLAUDS-HSC-SSP-DUNES$^2$ joint data
The Vera C. Rubin Observatory will conduct the Legacy Survey of Space and Time (LSST), delivering deep, multi-band ($ugrizy$) imaging data across 18,000 square degrees over the next decade. Before this ultra-wide-field survey, we constructed a broad-band Ly$α$ imaging toward 483 SDSS/BOSS quasars at $z=$ 1.9-3.0, using deep, wide-field ultraviolet to near-infrared ($u$-to-$K$) data from the Hyper Suprime-Cam Subaru Strategic Survey (HSC-SSP), the CFHT Large Area U-band Deep Survey (CLAUDS), th…

Lonely Little Red Dots: Challenges to the AGN-nature of little red dots through their clustering and spectral energy distributions
Mar\'ia de las Mercedes Carranza Escudero, Christopher J. Conselice, Nathan Adams, Thomas Harvey, Duncan Austin, Peter Behroozi, Leonardo Ferreira, Katherine Ormerod, Qiao Duan, James Trussler, Qiong Li, Lewi Westcott, Rogier A. Windhorst, Dan Coe, Seth H. Cohen, Cheng Cheng, Simon P. Driver, Brenda Frye, Lukas J. Furtak, Norman A. Grogin, Nimish P. Hat…

Lonely Little Red Dots: Challenges to the AGN-nature of little red dots through their clustering and spectral energy distributions
Observations with the James Webb Space Telescope (JWST) reveal a previously unseen population of compact red objects, known as ``little red dots`` (LRDs). We study a new photometrically selected sample of 124 LRDs in the redshift range $z$ $\sim$ 3 - 10 selected from NIRCam coverage of the CEERS, NEP-TDF, JADES and JEMS surveys. For JADES, the NEP-TDF and CEERS, we compare SED models with and without AGN components and analyse the impact of an AGN component on the goodness of fit using the Baye…