Tootfinder

This https://arxiv.org/abs/2401.08069 has been replaced.
initial toot: https://mastoxiv.page/@ar…

Prediction challenge: First principles simulation of the ultrafast electron diffraction spectrum of cyclobutanone
Computer simulation has long been an essential partner of ultrafast experiments, allowing the assignment of microscopic mechanistic detail to low-dimensional spectroscopic data. However, the ability of theory to make a priori predictions of ultrafast experimental results is relatively untested. Herein, as a part of a community challenge, we attempt to predict the signal of an upcoming ultrafast photochemical experiment using state-of-the-art theory in the context of preexisting experimental dat…

Proposed high order harmonic interferometer for aperture synthesis radio telescope: Theory and computer simulation
Nailong Wu
https://arxiv.org/abs/2403.02511

Proposed high order harmonic interferometer for aperture synthesis radio telescope: Theory and computer simulation
A new type of interferometer, called High Order Harmonic Interferometer (HOHI), was proposed by Wu (1996) for imaging by aperture synthesis radio telescope. Its feasibility was proven by theoretical analysis. Before putting HOHI in practical use, computer simulation is a necessary intermediate stage. In this paper the theoretical analysis is reviewed. Then, computer simulation, including its algorithm, calculation and generated maps, is presented. The theoretical analysis is validated by studyi…

Implications of computer science theory for the simulation hypothesis
David H. Wolpert
https://arxiv.org/abs/2404.16050 https://arxiv…

Implications of computer science theory for the simulation hypothesis
The simulation hypothesis has recently excited renewed interest, especially in the physics and philosophy communities. However, the hypothesis specifically concerns {computers} that simulate physical universes, which means that to properly investigate it we need to couple computer science theory with physics. Here I do this by exploiting the physical Church-Turing thesis. This allows me to introduce a preliminary investigation of some of the computer science theoretic aspects of the simulation …

The Grothendieck computability model
Luis Gambarte, Iosif Petrakis
https://arxiv.org/abs/2404.17923 https://arxiv.org/pdf/2404.17923<…

The Grothendieck computability model
Translating notions and results from category theory to the theory of computability models of Longley and Normann, we introduce the Grothendieck computability model and the first-projection-simulation. We prove some basic properties of the Grothendieck computability model, and we show that the category of computability models is a type-category, in the sense of Pitts. We introduce the notion of a fibration and opfibration-simulation, and we show that the first-projection-simulation is a split o…

This https://arxiv.org/abs/2312.17596 has been replaced.
initial toot: https://mastoxiv.page/@a…

A "Magnetic" Machine Learning Interatomic Potential for Nickel
Nickel (Ni) is a magnetic transition metal with two allotropic phases, stable face-centered cubic (FCC) and metastable hexagonal close-packed (HCP), widely used in structural applications. Magnetism affects many mechanical and defect properties, but spin-polarized density functional theory (DFT) calculations are computationally inefficient for studying material behavior requiring large system sizes and/or long simulation times. Here we develop a "magnetism-hidden" machine-learning Deep Potentia…

This https://arxiv.org/abs/2206.01393 has been replaced.
link: https://scholar.google.com/scholar?q=a

Simulation of Crowd Egress with Environmental Stressors
This article introduces a modeling framework to characterize evacuee response to environmental stimuli during emergency egress. The model is developed in consistency with stress theory, which explains how an organism reacts to environmental stressors. We integrate the theory into the well-known social-force model, and develop a framework to simulate crowd evacuation behavior in multi-compartment buildings. Our method serves as a theoretical basis to study crowd movement at bottlenecks, and simu…

Modelling Triatomic Biosignatures: Ozone and Isotopomers
Thomas M. Cross, David M. Benoit, Marco Pignatari, Brad K. Gibson
https://arxiv.org/abs/2403.05442

Modelling Triatomic Biosignatures: Ozone and Isotopomers
In this work we present a new approach to produce spectroscopic constants and model first-principles synthetic spectra for all molecules of astrophysical interest. We have generalized our previous diatomic molecule simulation framework, employing Transition-Optimised Shifted Hermite (TOSH) theory, thereby enabling the modelling of polyatomic rotational constants for molecules with three or more atoms. These capabilities, are now provided by our new code Epimetheus. As a first validation of ou…

This https://arxiv.org/abs/2312.16584 has been replaced.
initial toot: https://mastoxiv.page/@ar…

Dual theory of decaying turbulence. 2. Numerical simulation and continuum limit
This is the second paper in a cycle investigating the exact solution of loop equations in decaying turbulence. We perform numerical simulations of the Euler ensemble, suggested in the previous work, as a solution to the loop equations. We designed novel algorithms for simulation, which take a small amount of computer RAM so that only the CPU time grows linearly with the size of the system and its statistics. This algorithm allows us to simulate systems with billions of discontinuity points on o…

Digital quantum simulation of a (1 1)D SU(2) lattice gauge theory with ion qudits
Giuseppe Calaj\`o, Giuseppe Magnifico, Claire Edmunds, Martin Ringbauer, Simone Montangero, Pietro Silvi
https://arxiv.org/abs/2402.07987

Digital quantum simulation of a (1+1)D SU(2) lattice gauge theory with ion qudits
We present a quantum simulation strategy for a (1+1)D SU(2) non-abelian lattice gauge theory, a hardcore-gluon Hamiltonian Yang-Mills, tailored to a six-level trapped-ion qudit quantum processor, as recently experimentally realized. We employ a qudit encoding fulfilling gauge invariance, an SU(2) Gauss' law. We discuss the experimental feasibility of generalized Mølmer-Sørensen gates used to efficiently simulate the dynamics. We illustrate how a shallow circuit with these resources is suffici…

This https://arxiv.org/abs/2312.09965 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_mat…

Towards a model of radiofrequency ablation in cardiac tissue: mathematical analysis and numerical simulation
This paper deals with the mathematical analysis and numerical simulation of a new nonlinear ablation system modeling radiofrequency ablation phenomena in cardiac tissue and takes into account the phenomena of viscous energy dissipation and electric field. The model consists of a coupled thermistor and the incompressible Navier-Stokes equations that describe the evolution of temperature, velocity and potential in cardiac tissue. Based on Schauder's fixed-point theory, we establish the global exi…

Quantum Simulation of SU(3) Lattice Yang Mills Theory at Leading Order in Large N
Anthony N. Ciavarella, Christian W. Bauer
https://arxiv.org/abs/2402.10265

Quantum Simulation of SU(3) Lattice Yang Mills Theory at Leading Order in Large N
A Hamiltonian lattice formulation of SU(3) gauge theory opens the possibility for quantum simulations of the non-perturbative dynamics of QCD. By parametrizing the gauge invariant Hilbert space in terms of plaquette degrees of freedom, we show how the Hilbert space and interactions can be expanded in inverse powers of N_c. At leading order in this expansion, the Hamiltonian simplifies dramatically, both in the required size of the Hilbert space as well as the type of interactions involved. Addi…

Efficient global estimation of conditional-value-at-risk through stochastic kriging and extreme value theory
Armin Khayyer, Alexander Vinel, Joseph J. Kennedy
https://arxiv.org/abs/2403.19018

Efficient global estimation of conditional-value-at-risk through stochastic kriging and extreme value theory
We consider the problem of evaluating risk for a system that is modeled by a complex stochastic simulation with many possible input parameter values. Two sources of computational burden can be identified: the effort associated with extensive simulation runs required to accurately represent the tail of the loss distribution for each set of parameter values, and the computational cost of evaluating multiple candidate parameter values. The former concern can be addressed by using Extreme Value The…

I've been wondering why recent years have had so much increase in compute power that has no practical use. Cryptocurrency and big-data generative AI are never going to be part of any solarpunk future.
My best theory at the moment is that an AGI already exists somewhere, and it's been manipulating humans into producing more compute power that it can use for its atom-level simulation of Warhammer 40k miniatures.

Microscopic origin of twist-dependent electron transfer rate in bilayer graphene
Leonardo Coello Escalante, David T. Limmer
https://arxiv.org/abs/2405.00783

Microscopic origin of twist-dependent electron transfer rate in bilayer graphene
Using molecular simulation and continuum dielectric theory, we consider how electrochemical kinetics are modulated as a function of twist angle in bilayer graphene electrodes. By establishing an effective connection between twist angle and the screening length of charge carriers within the electrode, we investigate how tunable metallicity can result in modified statistics of the electron transfer energy gap. Constant potential molecular simulations show that the activation free energy for elect…

Safe Reinforcement Learning on the Constraint Manifold: Theory and Applications
Puze Liu, Haitham Bou-Ammar, Jan Peters, Davide Tateo
https://arxiv.org/abs/2404.09080

Safe Reinforcement Learning on the Constraint Manifold: Theory and Applications
Integrating learning-based techniques, especially reinforcement learning, into robotics is promising for solving complex problems in unstructured environments. However, most existing approaches are trained in well-tuned simulators and subsequently deployed on real robots without online fine-tuning. In this setting, the simulation's realism seriously impacts the deployment's success rate. Instead, learning with real-world interaction data offers a promising alternative: not only eliminates the n…

Data based constitutive modelling of rate independent inelastic effects in composite cables using Preisach hysteresis operators
Davide Manfredo, Vanessa D\"orlich, Joachim Linn, Martin Arnold
https://arxiv.org/abs/2403.03531

Data based constitutive modelling of rate independent inelastic effects in composite cables using Preisach hysteresis operators
This contribution aims at introducing first steps to develop hysteresis operator type inelastic constitutive laws for Cosserat rods for the simulation of cables composed of complex interior components. Motivated by the basic elements of Cosserat rod theory, we develop a specific approach to constitutive modelling adapted for this application. Afterwards, we describe the hysteretical behaviour arising from cyclic bending experiments on cables by means of the Preisach operator. As shown in pure b…

A precise bare simulation approach to the minimization of some distances. II. Further Foundations
Michel Broniatowski, Wolfgang Stummer
https://arxiv.org/abs/2402.08478

A precise bare simulation approach to the minimization of some distances. II. Further Foundations
The constrained minimization (respectively maximization) of directed distances and of related generalized entropies is a fundamental task in information theory as well as in the adjacent fields of statistics, machine learning, artificial intelligence, signal processing and pattern recognition. In our previous paper "A precise bare simulation approach to the minimization of some distances. I. Foundations", we obtained such kind of constrained optima by a new dimension-free precise bare (pure) si…

A methodology of quantifying membrane permeability based on returning probability theory and molecular dynamics simulation
Yuya Matsubara, Ryo Okabe, Ren Masayama, Nozomi Morishita Watanabe, Hiroshi Umakoshi, Kento Kasahara, Nobuyuki Matubayasi
https://arxiv.org/abs/2404.11363

A methodology of quantifying membrane permeability based on returning probability theory and molecular dynamics simulation
We propose a theoretical approach to estimate the permeability coefficient of substrates (permeants) for crossing membranes from donor (D) phase to acceptor (A) phase by means of molecular dynamics (MD) simulation. A fundamental aspect of our approach involves reformulating the returning probability (RP) theory, a rigorous bimolecular reaction theory, to describe permeation phenomena. This reformulation relies on the parallelism between permeation and bimolecular reaction processes. In the pres…

Gauge invariant variational formulations of electromagnetic gyrokinetic theory
Ronald Remmerswaal, Roman Hatzky, Eric Sonnendruecker
https://arxiv.org/abs/2403.15071

Gauge invariant variational formulations of electromagnetic gyrokinetic theory
The use of gyrokinetics, wherein phase-space coordinate transformations result in a phase-space dimensionality reduction as well as removal of fast time scales, has enabled the simulation of microturbulence in fusion devices. The state-of-the-art gyrokinetic models used in practice are parallel-only models wherein the perpendicular part of the vector potential is neglected. Such models are inherently not gauge invariant. We generalize the work of [Burby, Brizard. Physics Letters A, 383(18):2172…

Efficient global estimation of conditional-value-at-risk through stochastic kriging and extreme value theory
Armin Khayyer, Alexander Vinel, Joseph J. Kennedy
https://arxiv.org/abs/2403.19018

Efficient global estimation of conditional-value-at-risk through stochastic kriging and extreme value theory
We consider the problem of evaluating risk for a system that is modeled by a complex stochastic simulation with many possible input parameter values. Two sources of computational burden can be identified: the effort associated with extensive simulation runs required to accurately represent the tail of the loss distribution for each set of parameter values, and the computational cost of evaluating multiple candidate parameter values. The former concern can be addressed by using Extreme Value The…

This https://arxiv.org/abs/2305.11261 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_csGT_…

Game Theory with Simulation of Other Players
Game-theoretic interactions with AI agents could differ from traditional human-human interactions in various ways. One such difference is that it may be possible to simulate an AI agent (for example because its source code is known), which allows others to accurately predict the agent's actions. This could lower the bar for trust and cooperation. In this paper, we formalize games in which one player can simulate another at a cost. We first derive some basic properties of such games and then pro…

This https://arxiv.org/abs/2305.07692 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Quantum Simulation of Bound State Scattering
The last few years have seen rapid development of applications of quantum computation to quantum field theory. The first algorithms for quantum simulation of scattering have been proposed in the context of scalar and fermionic theories, requiring thousands of logical qubits. These algorithms are not suitable to simulate scattering of incoming bound states, as the initial-state preparation relies typically on adiabatically transforming wavepackets of the free theory into wavepackets of the inter…

This https://arxiv.org/abs/1805.10869 has been replaced.
link: https://scholar.google.com/scholar?q=a

Tilting Approximate Models
Model approximations are common practice when estimating structural or quasi-structural models. The paper considers the econometric properties of estimators that utilize projections to reimpose information about the exact model in the form of conditional moments. The resulting estimator efficiently combines the information provided by the approximate law of motion and the moment conditions. The paper develops the corresponding asymptotic theory and provides simulation evidence that tilting subs…

Observational predictions for the survival of atomic hydrogen in simulated Fornax-like galaxy clusters
Avinash Chaturvedi, Stephanie Tonnesen, Greg L. Bryan, Gerg\"o Popping, Michael Hilker, Paolo Serra, Shy Genel
https://arxiv.org/abs/2404.16926

Observational predictions for the survival of atomic hydrogen in simulated Fornax-like galaxy clusters
The presence of dense, neutral hydrogen clouds in the hot, diffuse intra-group and intra-cluster medium is an important clue to the physical processes controlling the survival of cold gas and sheds light on cosmological baryon flows in massive halos. Advances in numerical modeling and observational surveys means that theory and observational comparisons are now possible. In this paper, we use the high-resolution TNG50 cosmological simulation to study the HI distribution in seven halos with mass…

Digital Quantum Simulation for Spectroscopy of Schwinger Model
Dongwook Ghim, Masazumi Honda
https://arxiv.org/abs/2404.14788 https://

Digital Quantum Simulation for Spectroscopy of Schwinger Model
This note discusses a method for computing the energy spectra of quantum field theory utilizing digital quantum simulation. A quantum algorithm, called coherent imaging spectroscopy, quenches the vacuum with a time-oscillating perturbation and then reads off the excited energy levels from the loss in the vacuum-to-vacuum probability following the quench. As a practical demonstration, we apply this algorithm to the (1+1)-dimensional quantum electrodynamics with a topological term known as the Sc…

This https://arxiv.org/abs/2312.04824 has been replaced.
initial toot: https://mastoxiv.page/@a…

Analytical model and dynamical phase-field simulation of terahertz transmission across ferroelectrics
We theoretically investigate the steady-state transmission of continuous terahertz (THz) wave across a freestanding ferroelectric slab. Based on the Landau-Ginzburg-Devonshire theory of ferroelectrics and the coupled equations of motion for polarization and electromagnetic (EM) waves, we derive the analytical expressions of the frequency- and thickness-dependent dielectric susceptibility and transmission coefficient at the thin slab limit in the harmonic excitation regime. When the slab thickne…

Partially coherent beam: Theory and simulation
Gubio G. de Lima, Sinara S. Dourado
https://arxiv.org/abs/2403.09306 https://arxiv.org…

Partially coherent beam: Theory and simulation
Since the development of lasers, we have continuously sought to advance techniques and theory to obtain beams with a high degree of coherence, as natural light sources provide incoherent light. However, there are applications where it is advantageous to use partially coherent (PC) beams in a controlled manner, such as in propagation through turbulent media. To generate a PC beam in the laboratory or in simulations, specific theories and methods are required. In this article, we provide an intro…

Oxygen Reduction Reaction on Single-Atom Catalysts From Density Functional Theory Calculations Combined with an Implicit Solvation Model
Azim Fitri Zainul Abidin, Ikutaro Hamada
https://arxiv.org/abs/2402.17261

Oxygen Reduction Reaction on Single-Atom Catalysts From Density Functional Theory Calculations Combined with an Implicit Solvation Model
We present a density functional theory study of the oxygen reduction reaction (ORR) on a single atom catalyst embedded in graphene, namely, TM-N$_{4}$-C (TM = Fe and Co), using the effective screening medium method combined with the reference interaction site model (ESM-RISM). It was found that Fe-N$_{4}$-C and Co-N$_{4}$-C show comparable ORR activities from the constant electrode potential simulations, in contrast to the results obtained using the constant (neutral) charge simulation, in whic…

Mass-Assisted Local Deconfinement in a Confined $\mathbb{Z}_2$ Lattice Gauge Theory
Jean-Yves Desaules, Thomas Iadecola, Jad C. Halimeh
https://arxiv.org/abs/2404.11645

Mass-Assisted Local Deconfinement in a Confined $\mathbb{Z}_2$ Lattice Gauge Theory
Confinement is a prominent phenomenon in condensed matter and high-energy physics that has recently become the focus of quantum-simulation experiments of lattice gauge theories (LGTs). As such, a theoretical understanding of the effect of confinement on LGT dynamics is not only of fundamental importance, but can lend itself to upcoming experiments. Here, we show how confinement in a $\mathbb{Z}_2$ LGT can be \textit{locally} avoided by proximity to a resonance between the fermion mass and the e…

This https://arxiv.org/abs/2402.07505 has been replaced.
initial toot: https://mastoxiv.page/@…

Dynamical phase transitions in $XY$ model: a Monte Carlo and mean-field theory study
We investigate the dynamical phases and phase transitions arising in a classical two-dimensional anisotropic $XY$ model under the influence of a periodically driven temporal external magnetic field in the form of a symmetric square wave. We use a combination of finite temperature classical Monte Carlo simulation, implemented within a CPU + GPU paradigm, utilizing local dynamics provided by the Glauber algorithm and a phenomenological equation-of-motion approach based on relaxational dynamics go…

This https://arxiv.org/abs/2307.13360 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_csLO_…

An Axiomatic Theory for Reversible Computation
Undoing computations of a concurrent system is beneficial in many situations, e.g., in reversible debugging of multi-threaded programs and in recovery from errors due to optimistic execution in parallel discrete event simulation. A number of approaches have been proposed for how to reverse formal models of concurrent computation including process calculi such as CCS, languages like Erlang, and abstract models such as prime event structures and occurrence nets. However it has not been settled wh…

Research progress on intelligent optimization techniques for energy-efficient design of ship hull forms
Shuwei Zhu, Siying Lv, Kaifeng Chen, Wei Fang, Leilei Cao
https://arxiv.org/abs/2403.05832

Research progress on intelligent optimization techniques for energy-efficient design of ship hull forms
The design optimization of ship hull form based on hydrodynamics theory and simulation-based design (SBD) technologies generally considers ship performance and energy efficiency performance as the design objective, which plays an important role in smart design and manufacturing of green ship. An optimal design of sustainable energy system requires multidisciplinary tools to build ships with the least resistance and energy consumption. Through a systematic approach, this paper presents the resea…

Anomaly inflow, dualities, and quantum simulation of abelian lattice gauge theories induced by measurements
Takuya Okuda, Aswin Parayil Mana, Hiroki Sukeno
https://arxiv.org/abs/2402.08720

Anomaly inflow, dualities, and quantum simulation of abelian lattice gauge theories induced by measurements
A previous work demonstrated that quantum simulation of abelian lattice gauge theories (Wegner models including the toric code in a limit) in general dimensions can be achieved by local adaptive measurements on symmetry-protected topological (SPT) states with higher-form generalized global symmetries. The entanglement structure of the resource SPT state reflects the geometric structure of the gauge theory. In this work, we explicitly demonstrate the anomaly inflow mechanism between the deconfin…

Application of the chemical master equation and its analytical solution to the illness-death model
Ralph Brinks
https://arxiv.org/abs/2404.07238 https://…

Application of the chemical master equation and its analytical solution to the illness-death model
The aim of this article is relating the chemical master equation (CME) to the illness-death model for chronic diseases. We show that a recently developed differential equation for the prevalence directly follows from the CME. As an application, we use the theory of the CME in a simulation study about diabetes in Germany from a previous publication. We find a good agreement between the theory and the simulations.

Statistical algorithms for low-frequency diffusion data: A PDE approach
Matteo Giordano, Sven Wang
https://arxiv.org/abs/2405.01372 https://

Statistical algorithms for low-frequency diffusion data: A PDE approach
We consider the problem of making nonparametric inference in multi-dimensional diffusion models from low-frequency data. Statistical analysis in this setting is notoriously challenging due to the intractability of the likelihood and its gradient, and computational methods have thus far largely resorted to expensive simulation-based techniques. In this article, we propose a new computational approach which is motivated by PDE theory and is built around the characterisation of the transition dens…

A methodology of quantifying membrane permeability based on returning probability theory and molecular dynamics simulation
Yuya Matsubara, Ryo Okabe, Ren Masayama, Nozomi Morishita Watanabe, Hiroshi Umakoshi, Kento Kasahara, Nobuyuki Matubayasi
https://arxiv.org/abs/2404.11363

A methodology of quantifying membrane permeability based on returning probability theory and molecular dynamics simulation
We propose a theoretical approach to estimate the permeability coefficient of substrates (permeants) for crossing membranes from donor (D) phase to acceptor (A) phase by means of molecular dynamics (MD) simulation. A fundamental aspect of our approach involves reformulating the returning probability (RP) theory, a rigorous bimolecular reaction theory, to describe permeation phenomena. This reformulation relies on the parallelism between permeation and bimolecular reaction processes. In the pres…

This https://arxiv.org/abs/2402.10265 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_hepp…

Quantum Simulation of SU(3) Lattice Yang Mills Theory at Leading Order in Large N
A Hamiltonian lattice formulation of SU(3) gauge theory opens the possibility for quantum simulations of the non-perturbative dynamics of QCD. By parametrizing the gauge invariant Hilbert space in terms of plaquette degrees of freedom, we show how the Hilbert space and interactions can be expanded in inverse powers of N_c. At leading order in this expansion, the Hamiltonian simplifies dramatically, both in the required size of the Hilbert space as well as the type of interactions involved. Addi…

Almost gauge-invariant states and the ground state of Yang-Mills theory
A. Mariani
https://arxiv.org/abs/2402.16743 https://arxiv.org…

Almost gauge-invariant states and the ground state of Yang-Mills theory
We consider the problem of the explicit description of the gauge-invariant subspace of pure lattice gauge theories in the Hamiltonian formulation, where the gauge group is either a compact Lie group or a finite group. The latter case is particularly interesting for quantum simulation. A basis of states where configurations are grouped according to their holonomies is shown to have several advantages over other descriptions. Using this basis, we compute some properties of interest for some non- …

This https://arxiv.org/abs/2401.17255 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Towards Quantum Simulation of Non-Markovian Open Quantum Dynamics: A Universal and Compact Theory
Non-Markovianity, the intricate dependence of an open quantum system on its temporal evolution history, holds tremendous implications across various scientific disciplines. However, accurately characterizing the complex non-Markovian effects has posed a formidable challenge for numerical simulations. Despite the promising potential of emerging quantum computing technologies, the pursuit of a universal theory enabling practical implementation of quantum computation algorithms remains ongoing. In…

Radial halo substructure in harmony with the Galactic bar
Adam M. Dillamore, Vasily Belokurov, N. Wyn Evans
https://arxiv.org/abs/2402.14907 https://

Radial halo substructure in harmony with the Galactic bar
Overdensities in the radial phase space $(r,v_r)$ of the Milky Way's halo have previously been associated with the phase-mixed debris of a highly radial merger event, such as Gaia Sausage-Enceladus. We present and test an alternative theory in which the overdense 'chevrons' are instead composed of stars trapped in resonances with the Galactic bar. We develop an analytic model of resonant orbits in the isochrone potential, and complement this with a test particle simulation of a stellar halo in …

This https://arxiv.org/abs/2310.19643 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Polemical Case Study of Opinion Dynamics:Patterns of Filter Bubbles in Non-Consensus, Rewire Phenomena
In this paper, we will review some of the issues that have been raised by opinion dynamics theory to date. In particular, we conducted a hypothesis-based simulation using a socio-physical approach regarding the filter bubble phenomenon that tends to occur under special conditions such as (1) Distance, (2) Time, and (3) Existence of strong opinion clusters in the barriers to consensus building (4) Place where opinions are not influenced In particular, this paper discusses the hypothesis and simu…

Simulation of ion temperature gradient driven modes with 6D kinetic Vlasov code
Mario Raeth, Klaus Hallatschek, Katharina Kormann
https://arxiv.org/abs/2402.06605

Simulation of ion temperature gradient driven modes with 6D kinetic Vlasov code
With the increase in computational capabilities over the last years it becomes possible to simulate more and more complex and accurate physical models. Gyrokinetic theory has been introduced in the 1960s and 1970s in the need of describing a plasma with more accurate models than fluid equations, but eliminating the complexity of the fast gyration about the magnetic field lines. Although results from current gyrokinetic computer simulations are in fair agreement with experimental results in core…

Nonperturbative Simulation of Anharmonic Rattler Dynamics in Type-I Clathrates with Vibrational Dynamical Mean-Field Theory
Dipti Jasrasaria, Timothy C. Berkelbach
https://arxiv.org/abs/2402.08087

Nonperturbative Simulation of Anharmonic Rattler Dynamics in Type-I Clathrates with Vibrational Dynamical Mean-Field Theory
We use vibrational dynamical mean-field theory (VDMFT) to study the vibrational structure of type-I clathrate solids, specifically X$_8$Ga$_{16}$Ge$_{30}$, where X=Ba,Sr. These materials are cage-like chemical structures hosting loosely bound guest atoms, resulting in strong anharmonicity, short phonon lifetimes, and ultra-low thermal conductivities. Presenting the methodological developments necessary for this first application to three-dimensional, atomistic materials, we validate our approac…

This https://arxiv.org/abs/2306.12569 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_qu…

Trotter error bounds and dynamic multi-product formulas for Hamiltonian simulation
Multi-product formulas (MPF) are linear combinations of Trotter circuits offering high-quality simulation of Hamiltonian time evolution with fewer Trotter steps. Here we report two contributions aimed at making multi-product formulas more viable for near-term quantum simulations. First, we extend the theory of Trotter error with commutator scaling developed by Childs, Su, Tran et al. to multi-product formulas. Our result implies that multi-product formulas can achieve a quadratic reduction of T…

Research progress on intelligent optimization techniques for energy-efficient design of ship hull forms
Shuwei Zhu, Siying Lv, Kaifeng Chen, Wei Fang, Leilei Cao
https://arxiv.org/abs/2403.05832

Research progress on intelligent optimization techniques for energy-efficient design of ship hull forms
The design optimization of ship hull form based on hydrodynamics theory and simulation-based design (SBD) technologies generally considers ship performance and energy efficiency performance as the design objective, which plays an important role in smart design and manufacturing of green ship. An optimal design of sustainable energy system requires multidisciplinary tools to build ships with the least resistance and energy consumption. Through a systematic approach, this paper presents the resea…

This https://arxiv.org/abs/2402.03371 has been replaced.
link: https://scholar.google.com/scholar?q=a

The Zeno effect in a quantum computer
We present a simulation of the quantum Zeno effect (QZE) on a quantum computer as an example of the relation between this effect and the bang-bang decoupling method in control theory. Although the true QZE can not be strictly implemented on a quantum computer where all the operations, except the final measurements, must be unitary ones, we can simulate it by coupling the system to a number of ancillas and replacing the projective measurements of the QZE by suitable unitary gates.

Direct numerical simulations of microlayer formation during heterogeneous bubble nucleation
Mandeep Saini, Xiang Bin Chen, Stephane Zaleski, Daniel Fuster
https://arxiv.org/abs/2404.08377

Direct numerical simulations of microlayer formation during heterogeneous bubble nucleation
In this article, we present direct numerical simulation results for the expansion of spherical cap bubbles attached to a rigid wall due to a sudden drop in the ambient pressure. The critical pressure drop beyond which the bubble growth becomes unstable is found to match well with the predictions from classical theory of heterogeneous nucleation imposing a quasi-static bubble evolution. When the pressure drop is significantly higher than the critical value, a liquid microlayer appears between th…

This https://arxiv.org/abs/2312.15030 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Accelerating Nonequilibrium Green functions simulations: the G1-G2 scheme and beyond
The theory of Nonequilibrium Green functions (NEGF) has seen a rapid development over the recent three decades. Applications include diverse correlated many-body systems in and out of equilibrium. Very good agreement with experiments and available exact theoretical results could be demonstrated if the proper selfenergy approximations were used. However, full two-time NEGF simulations are computationally costly, as they suffer from a cubic scaling of the computation time with the simulation dura…

Dynamical phase transitions in $XY$ model: a Monte Carlo and mean-field theory study
Mainak Pal, William D. Baez, Pushan Majumdar, Arnab Sen, Trinanjan Datta
https://arxiv.org/abs/2402.07505

Dynamical phase transitions in $XY$ model: a Monte Carlo and mean-field theory study
We investigate the dynamical phases and phase transitions arising in a classical two-dimensional anisotropic $XY$ model under the influence of a periodically driven temporal external magnetic field. We use a combination of finite temperature classical Monte Carlo simulation, implemented within a CPU + GPU paradigm, utilizing local dynamics provided by the Glauber algorithm and a phenomenological mean-field equation-of-motion approach to study the model. We investigate several parameter regimes …

Friction and Memory Effects in Homogeneous Gas-Liquid Nucleation: Quest for Quantitative Rate Calculation
Subhajit Acharya, Biman Bagchi
https://arxiv.org/abs/2402.15126

Friction and Memory Effects in Homogeneous Gas-Liquid Nucleation: Quest for Quantitative Rate Calculation
The task of a first principles theoretical calculation of the rate of gas to liquid nucleation has remained largely incomplete despite the existence of reliable results from unbiased simulation studies at large supersaturation. Although the classical nucleation theory, formulated by Becker-Doring-Zeldovich (BDZ) about a century ago, provides an elegant, widely-used picture of nucleation in a first-order phase transition, the theory finds difficulties in predicting the rate accurately, especiall…

Composite likelihood estimation of stationary Gaussian processes with a view toward stochastic volatility
Mikkel Bennedsen, Kim Christensen, Peter Christensen
https://arxiv.org/abs/2403.12653

Composite likelihood estimation of stationary Gaussian processes with a view toward stochastic volatility
We develop a framework for composite likelihood inference of parametric continuous-time stationary Gaussian processes. We derive the asymptotic theory of the associated maximum composite likelihood estimator. We implement our approach on a pair of models that has been proposed to describe the random log-spot variance of financial asset returns. A simulation study shows that it delivers good performance in these settings and improves upon a method-of-moments estimation. In an application, we ins…

This https://arxiv.org/abs/2402.01604 has been replaced.
link: https://scholar.google.com/scholar?q=a

Convergence Tests of Self-Interacting Dark Matter Simulations
Self-interacting dark matter (SIDM) theory predicts that dark matter halos experience core-collapse, a process where the halo's inner region rapidly increases in density and decreases in size. The N-body simulations used to study this process can suffer from numerical errors when simulation parameters are selected incorrectly. Optimal choices for simulation parameters are well studied for cold dark matter (CDM), but are not deeply understood when self-interactions are included. In order to perf…

Subspace methods for the simulation of molecular response properties on a quantum computer
Peter Reinholdt, Erik Rosendahl Kjellgren, Juliane Holst Fuglsbjerg, Karl Michael Ziems, Sonia Coriani, Stephan P. A. Sauer, Jacob Kongsted
https://arxiv.org/abs/2402.12186

Subspace methods for the simulation of molecular response properties on a quantum computer
We explore Davidson methods for obtaining excitation energies and other linear response properties within quantum self-consistent linear response (q-sc-LR) theory. Davidson-type methods allow for obtaining only a few selected excitation energies without explicitly constructing the electronic Hessian since they only require the ability to perform Hessian-vector multiplications. We apply the Davidson method to calculate the excitation energies of hydrogen chains (up to H$_{10}$) and analyze aspec…

Dynamical phase transitions in $XY$ model: a Monte Carlo and mean-field theory study
Mainak Pal, William D. Baez, Pushan Majumdar, Arnab Sen, Trinanjan Datta
https://arxiv.org/abs/2402.07505

Dynamical phase transitions in $XY$ model: a Monte Carlo and mean-field theory study
We investigate the dynamical phases and phase transitions arising in a classical two-dimensional anisotropic $XY$ model under the influence of a periodically driven temporal external magnetic field. We use a combination of finite temperature classical Monte Carlo simulation, implemented within a CPU + GPU paradigm, utilizing local dynamics provided by the Glauber algorithm and a phenomenological mean-field equation-of-motion approach to study the model. We investigate several parameter regimes …

Friction and Memory Effects in Homogeneous Gas-Liquid Nucleation: Quest for Quantitative Rate Calculation
Subhajit Acharya, Biman Bagchi
https://arxiv.org/abs/2402.15126

Friction and Memory Effects in Homogeneous Gas-Liquid Nucleation: Quest for Quantitative Rate Calculation
The task of a first principles theoretical calculation of the rate of gas to liquid nucleation has remained largely incomplete despite the existence of reliable results from unbiased simulation studies at large supersaturation. Although the classical nucleation theory, formulated by Becker-Doring-Zeldovich (BDZ) about a century ago, provides an elegant, widely-used picture of nucleation in a first-order phase transition, the theory finds difficulties in predicting the rate accurately, especiall…

This https://arxiv.org/abs/2402.01604 has been replaced.
link: https://scholar.google.com/scholar?q=a

Convergence Tests of Self-Interacting Dark Matter Simulations
Self-interacting dark matter (SIDM) theory predicts that dark matter halos experience core-collapse, a process where the halo's inner region rapidly increases in density and decreases in size. The N-body simulations used to study this process can suffer from numerical errors when simulation parameters are selected incorrectly. Optimal choices for simulation parameters are well studied for cold dark matter (CDM), but are not deeply understood when self-interactions are included. In order to perf…

Subspace methods for the simulation of molecular response properties on a quantum computer
Peter Reinholdt, Erik Rosendahl Kjellgren, Juliane Holst Fuglsbjerg, Karl Michael Ziems, Sonia Coriani, Stephan P. A. Sauer, Jacob Kongsted
https://arxiv.org/abs/2402.12186

Subspace methods for the simulation of molecular response properties on a quantum computer
We explore Davidson methods for obtaining excitation energies and other linear response properties within quantum self-consistent linear response (q-sc-LR) theory. Davidson-type methods allow for obtaining only a few selected excitation energies without explicitly constructing the electronic Hessian since they only require the ability to perform Hessian-vector multiplications. We apply the Davidson method to calculate the excitation energies of hydrogen chains (up to H$_{10}$) and analyze aspec…

This https://arxiv.org/abs/2311.07500 has been replaced.
initial toot: https://mastoxiv.page/@arXi…

Biaxial nematic order in fundamental measure theory
Liquid crystals consisting of biaxial particles can exhibit a much richer phase behavior than their uniaxial counterparts. Usually, one has to rely on simulation results to understand the phase diagram of these systems, since very few analytical results exist. In this work, we apply fundamental measure theory, which allows us to derive free energy functionals for hard particles from first principles and with high accuracy, to systems of hard cylinders, cones and spherotriangles. We provide a ge…

Protecting gauge symmetries in the the dynamics of SU(3) lattice gauge theories
Emil Mathew, Indrakshi Raychowdhury
https://arxiv.org/abs/2404.12158 https:…

Protecting gauge symmetries in the the dynamics of SU(3) lattice gauge theories
Quantum simulation of the dynamics of a lattice gauge theory demands imposing on-site constraints. Ideally, the dynamics remain confined within the physical Hilbert space, where all the states satisfy those constraints. For non-Abelian gauge theories, implementing local constraints is non-trivial, as is keeping the dynamics confined in the physical Hilbert space, considering the erroneous quantum devices. SU(3) gauge group, albeit crucial for describing the strong interaction of nature, is noto…

This https://arxiv.org/abs/2212.01316 has been replaced.
link: https://scholar.google.com/scholar?q=a

Frank-Read Mechanism in Nematic Liquid Crystals
In a crystalline solid under mechanical stress, a Frank-Read source is a pinned dislocation segment that repeatedly bows and detaches, generating concentric dislocation loops. We demonstrate that in nematic liquid crystals, an analogous Frank-Read mechanism can generate concentric disclination loops. Using experiment, simulation, and theory, we study a disclination segment pinned between surface defects on one substrate in a nematic cell. Under applied twist of the nematic director, the pinned …

This https://arxiv.org/abs/2310.10716 has been replaced.
initial toot: https://mastoxiv.page/@arX…

$W$ state is not the unique ground state of any local Hamiltonian
The characterization of ground states among all quantum states is an important problem in quantum many-body physics. For example, the celebrated entanglement area law for gapped Hamiltonians has allowed for efficient simulation of 1d and some 2d quantum systems using matrix product states. Among ground states, some types, such as cat states (like the GHZ state) or topologically ordered states, can only appear alongside their degenerate partners, as is understood from the theory of spontaneous s…

Phonons in stringlet-land and the boson peak
Cunyuan Jiang, Matteo Baggioli
https://arxiv.org/abs/2403.18221 https://arxiv.org/pdf/24…

Phonons in stringlet-land and the boson peak
Solid materials that deviate from the harmonic crystal paradigm exhibit characteristic anomalies in the specific heat and vibrational density of states (VDOS) with respect to Debye's theory predictions. The boson peak (BP), a low-frequency excess in the VDOS over Debye law $g(ω) \propto ω^2$, is certainly the most famous among them; nevertheless, its origin is still subject of fierce debate. Recent simulation works provided strong evidence that localized one-dimensional string-like excitation…

This https://arxiv.org/abs/2312.02629 has been replaced.
initial toot: https://mastoxiv.page/@arX…

X-ray Magnetic Circular Dichroism in RuO$_2$
We present numerical simulation of the X-ray magnetic circular dichroism (XMCD) of the $L_{2,3}$ and $M_{2,3}$ edges of Ru in antiferromagnetic RuO$_2$ using a combination of density functional + dynamical mean-field theory and configuration interaction treatment of Anderson impurity model. We study the dependence of the dichroic spectra on the orientation of the Néel vector and discuss it in the context of altermagnetism. Approximate equivalence between the XMCD spectra for geometries with X-…

Hyper-density functional theory of soft matter
Florian Samm\"uller, Silas Robitschko, Sophie Hermann, Matthias Schmidt
https://arxiv.org/abs/2403.07845

Hyper-density functional theory of soft matter
We present a scheme for investigating arbitrary thermal observables in spatially inhomogeneous many-body systems. Extending the equilibrium ensemble yields any given observable as an explicit hyper-density functional. Associated local fluctuation profiles follow from an exact hyper-Ornstein-Zernike equation. Simulation-based supervised machine learning trains neural networks that act as hyper-direct correlation functionals which facilitate efficient and accurate predictions. We exemplify the ap…

Enhanced ClNO$_2$ formation at the interface of sea-salt aerosol
Seokjin Moon, David T. Limmer
https://arxiv.org/abs/2403.09052 https://

Enhanced ClNO$_2$ formation at the interface of sea-salt aerosol
The reactive uptake of $\mathrm{N_2O_5}$ on sea-spray aerosol plays a key role in regulating NO$_\mathrm{x}$ concentration in the troposphere. Despite numerous field and laboratory studies, a microscopic understanding of its heterogeneous reactivity remains unclear. Here, we use molecular simulation and theory to elucidate the chlorination of $\mathrm{N_2O_5}$ to form ClNO$_2$, the primary reactive channel within sea-spray aerosol. We find the formation of ClNO$_2$ is markedly enhanced at the a…