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Related papers: Transients from Initial Conditions: A Perturbative…

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We present a description for setting initial particle displacements and field values for simulations of arbitrary metric theories of gravity, for perfect and imperfect fluids with arbitrary characteristics. We extend the Zel'dovich…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-23 Wessel Valkenburg , Bin Hu

We perform a series of experiments to measure Lagrangian trajectories of settling and rising particles as they traverse a density interface of thickness $h$ using an index-matched water-salt-ethanol solution. The experiments confirm the…

Fluid Dynamics · Physics 2019-10-15 Lilly Verso , Maarten van Reeuwijk , Alexander Liberzon

We study map lattices coupled by collision and show how perturbations of transfer operators associated with the spatially periodic approximation of the model can be used to extract information about collisions per lattice unit. More…

Dynamical Systems · Mathematics 2022-01-31 Wael Bahsoun , Fanni M. Sélley

Inverse problems arise in situations where data is available, but the underlying model is not. It can therefore be necessary to infer the parameters of the latter starting from the former. Statistical mechanics offers a toolbox of…

Statistical Mechanics · Physics 2025-07-04 Stefano Bae , Dario Bocchi , Luca Maria Del Bono , Luca Leuzzi

Lithium superionic conductors (LSCs) are of major importance as solid electrolytes for next-generation all-solid-state lithium-ion batteries. While $ab$ $initio$ molecular dynamics have been extensively applied to study these materials,…

Numerical and analytic results for the exponent \theta describing the decay of the first return probability of an interface to its initial height are obtained for a large class of linear Langevin equations. The models are parametrized by…

Statistical Mechanics · Physics 2009-10-30 J. Krug , H. Kallabis , S. N. Majumdar , S. J Cornell , A. J. Bray , C. Sire

In previous works we proposed the Reverse Zeldovich Approximation (RZA) method, which can be used to estimate the cosmological initial conditions underlying the galaxy distribution in the Local Universe using peculiar velocity data. In this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Timur Doumler , Stefan Gottloeber , Yehuda Hoffman , Helene Courtois

We discuss parametric estimation of a degenerate diffusion system from time-discrete observations. The first component of the degenerate diffusion system has a parameter $\theta_1$ in a non-degenerate diffusion coefficient and a parameter…

Statistics Theory · Mathematics 2020-02-25 Arnaud Gloter , Nakahiro Yoshida

Motivated by recent developments in perturbative calculations of the nonlinear evolution of large-scale structure, we present an iterative algorithm to reconstruct the initial conditions in a given volume starting from the dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-01 Marcel Schmittfull , Tobias Baldauf , Matias Zaldarriaga

We present high--spatial resolution studies of the density field as predicted by Lagrangian perturbation approximations up to the third order. The first--order approximation is equivalent to the ``Zel'dovich approximation'' for the type of…

Astrophysics · Physics 2011-05-23 Thomas Buchert , Georgios Karakatsanis , Robert Klaffl , Peter Schiller

New generation galaxy surveys targeting constraints on local primordial non-Gaussianity (PNG) demand $N$-body simulations that accurately reproduce its effects. In this work, we explore various prescriptions for the initial conditions of…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Adrian G. Adame , Santiago Avila , Violeta Gonzalez-Perez , Oliver Hahn , Gustavo Yepes , Marc Manera

We chart a path toward solving for the nonlinear gravitational dynamics of cold dark matter by relying on a semiclassical description using the propagator. The evolution of the propagator is given by a Schr\"odinger equation, where the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-15 Cora Uhlemann , Cornelius Rampf , Mateja Gosenca , Oliver Hahn

Stability and robustness are critical for deploying Transformers in safety-sensitive settings. A principled way to enforce such behavior is to constrain the model's Lipschitz constant. However, approximation-theoretic guarantees for…

Machine Learning · Computer Science 2026-02-18 Takashi Furuya , Davide Murari , Carola-Bibiane Schönlieb

We propose a new method to recover the cosmological initial conditions of the presently observed galaxy distribution, which can serve to run constrained simulations of the Local Universe. Our method, the Reverse Zeldovich Approximation…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Timur Doumler , Yehuda Hoffman , Helene Courtois , Stefan Gottloeber

First-passage times in random walks have a vast number of diverse applications in physics, chemistry, biology, and finance. In general, environmental conditions for a stochastic process are not constant on the time scale of the average…

Statistical Mechanics · Physics 2018-06-13 Martin Falcke , V. Nicolai Friedhoff

The problem of structure estimation in graphical models with latent variables is considered. We characterize conditions for tractable graph estimation and develop efficient methods with provable guarantees. We consider models where the…

Machine Learning · Statistics 2013-04-23 Animashree Anandkumar , Ragupathyraj Valluvan

We have investigated the effect of the initial condition on the spreading exponents of the one-dimensional pair contact process (PCP) and threshold transfer process (TTP).The non-order field was found to exhibit critical fluctuations,…

Statistical Mechanics · Physics 2009-10-31 Geza Odor , J. F. Mendes , M. A. Santos , M. C. Marques

Machine learning models of accelerator systems (`surrogate models') are able to provide fast, accurate predictions of accelerator physics phenomena. However, approaches to date typically do not include measured input diagnostics, such as…

Accelerator Physics · Physics 2021-04-06 Lipi Gupta , Auralee Edelen , Nicole Neveu , Aashwin Mishra , Christopher Mayes , Young-Kee Kim

As a first step in the first passage problem for passive tracer in stratified porous media, we consider the case of a two-dimensional system consisting of two layers with different convection velocities. Using a lattice generating function…

Condensed Matter · Physics 2009-10-22 Jysoo Lee , Joel Koplik

Space-Time Projection (STP) is introduced as a data-driven forecasting approach for high-dimensional and time-resolved data. The method computes extended space-time proper orthogonal modes from training data spanning a prediction horizon…

Machine Learning · Computer Science 2025-04-01 Oliver T. Schmidt