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We consider the classical stochastic fluctuations of spacetime geometry induced by quantum fluctuations of massless non-conformal matter fields in the Early Universe. To this end, we supplement the stress-energy tensor of these fields with…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. Calzetta , A. Campos , E. Verdaguer

Recent rapid advances in single particle tracking and supercomputing techniques resulted in an unprecedented abundance of diffusion data exhibiting complex behaviours, such the presence of power law tails of the msd and memory functions,…

Statistical Mechanics · Physics 2018-10-08 Jakub Ślęzak

Two algorithms are proposed to simulate space-time Gaussian random fields with a covariance function belonging to an extended Gneiting class, the definition of which depends on a completely monotone function associated with the spatial…

Computation · Statistics 2019-12-05 Denis Allard , Xavier Emery , Céline Lacaux , Christian Lantuéjoul

We investigate piecewise-linear stochastic models as with regards to the probability distribution of functionals of the stochastic processes, a question which occurs frequently in large deviation theory. The functionals that we are looking…

Statistical Mechanics · Physics 2015-06-22 Yaming Chen , Wolfram Just

We consider a sparse high-dimensional varying coefficients model with random effects, a flexible linear model allowing covariates and coefficients to have a functional dependence with time. For each individual, we observe discretely sampled…

Statistics Theory · Mathematics 2021-10-14 Michael Law , Ya'acov Ritov

The precision of reaction-diffusion models for mesoscopic physical systems is limited by fluctuations. To account for this uncertainty, Van Kampen derived a stochastic Langevin-like reaction-diffusion equation that incorporates…

Statistical Mechanics · Physics 2018-11-28 Roman Belousov , Adrian Jacobo , A. J. Hudspeth

The background field equations for homogeneous and isotropic spacetime are derived in conformal scalar-tensor gravity. The background temporal evolution is entirely driven by the dynamical evolution of the scalar field, i.e. particle…

General Physics · Physics 2018-10-12 Meir Shimon

This paper derives and analyzes exact, nonlocal Langevin equations appropriate in a cosmological setting to describe the interaction of some collective degree of freedom with a surrounding ``environment.'' Formally, these equations are much…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Salman Habib , Henry E. Kandrup

Explosive growth in spatio-temporal data and its wide range of applications have attracted increasing interests of researchers in the statistical and machine learning fields. The spatio-temporal regression problem is of paramount importance…

Machine Learning · Computer Science 2020-09-15 Aniruddha Rajendra Rao , Qiyao Wang , Haiyan Wang , Hamed Khorasgani , Chetan Gupta

The paper examines stochastic diffusion within an expanding space-time framework. It starts with providing a rationale for the considered model and its motivation from cosmology where the expansion of space-time is used in modelling various…

Probability · Mathematics 2023-12-22 Philip Broadbridge , Illia Donhauzer , Andriy Olenko

In this work we present full Bayesian inference for a new flexible nonseparable class of cross-covariance functions for multivariate spatial data. A Bayesian test is proposed for separability of covariance functions which is much more…

Methodology · Statistics 2017-07-24 Rafael S. Erbisti , Thais C. O. Fonseca , Mariane B. Alves

Differential equations based on physical principals are used to represent complex dynamic systems in all fields of science and engineering. Through repeated use in both academics and industry, these equations have been shown to represent…

Methodology · Statistics 2022-09-08 Joshua S. North , Christopher K. Wikle , Erin M. Schliep

The longstanding question of how stochastic behaviour arises from deterministic Hamiltonian dynamics is of great importance, and any truly holistic theory must be capable of describing this transition. In this review, we introduce the…

Statistical Mechanics · Physics 2020-12-02 Gerard McCaul , Denys I. Bondar

The time evolution of correlation functions in statistical systems is described by an exact functional differential equation for the corresponding generating functionals. This allows for a systematic discussion of non-equilibrium physics…

High Energy Physics - Theory · Physics 2009-10-30 Christof Wetterich

A global solution of the Schr\"odinger equation, obtained recently within the wave operator formalism for explicitly time-dependent Hamiltonians [J. Phys. A: Math. Theor. 48, 225205 (2015)], is generalized to take into account the case of…

Quantum Physics · Physics 2016-04-20 Georges Jolicard , Arnaud Leclerc , David Viennot , John P. Killingbeck

Langevin dynamics has become a popular tool to simulate the Boltzmann equilibrium distribution. When the repartition of the Langevin equation involves the exact realization of the Ornstein-Uhlenbeck noise, in addition to the conventional…

Chemical Physics · Physics 2017-11-15 Dezhang Li , Xu Han , Yichen Chai , Cong Wang , Zifei Chen , Zhijun Zhang , Jian Liu , Jiushu Shao

We propose that space-time results from collapse of the wave function of macroscopic objects, in quantum dynamics. We first argue that there ought to exist a formulation of quantum theory which does not refer to classical time. We then…

General Relativity and Quantum Cosmology · Physics 2019-01-31 Tejinder P. Singh

Including the effect of thermal fluctuations in traditional computational fluid dynamics requires developing numerical techniques for solving the stochastic partial differential equations of fluctuating hydrodynamics. These Langevin…

Computational Physics · Physics 2015-06-12 S. Delong , B. E. Griffith , E. Vanden-Eijnden , A. Donev

We introduce a constructive framework to learn effective Langevin equations from stationary time series. Unlike conventional approaches that require iterative calibration to match target statistics, our construction guarantees the observed…

Chaotic Dynamics · Physics 2026-02-16 Ludovico Theo Giorgini

The current cosmic time evolution of the Universe is described by the General Relativity theory when a cosmological principle is considered under a flat space time landscape. The set of known as Friedmann equations, contain the principles…

General Relativity and Quantum Cosmology · Physics 2022-06-20 Rodrigo Sandoval-Orozco , Celia Escamilla-Rivera