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Related papers: Late-time Structure of the Bunch-Davies FRW Wavefu…

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We describe scalar-bimetric theories where the dynamics of the Universe are governed by two separate metrics, each with an Einstein-Hilbert term. In this setting, the baryonic and dark matter components of the Universe couple to metrics…

General Relativity and Quantum Cosmology · Physics 2018-10-09 Philippe Brax , Patrick Valageas

We investigate the principles of quantum field theory using a stiff de Sitter space. We demonstrate that a non-unitary Lagrangian on a Euclidean AdS geometry can produce the perturbative expansion of late-time correlation functions to all…

High Energy Physics - Theory · Physics 2026-03-05 Sayantan Choudhury

We study large-scale structure formation in the presence of a quintessence component with zero speed of sound in the framework of Eulerian Perturbation Theory. Due to the absence of pressure gradients, quintessence and dark matter are…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Emiliano Sefusatti , Filippo Vernizzi

We introduce a time-dependent Eulerian-Lagrangian length-scale and an inverse locality hypothesis which explain scalings of second order one-particle Lagrangian structure functions observed in Kinematic Simulations (KS) of homogeneous…

Chaotic Dynamics · Physics 2007-05-23 M. A. I. Khan J. C. Vassilicos

The classical dynamics of collisionless cold dark matter, commonly described by fluid variables or a phase-space distribution, can be captured in a single semiclassical wavefunction. We illustrate how classical multi-streaming creates wave…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-16 Alex Gough , Cora Uhlemann

In this paper, we construct the beta function in the functorial formulation of two-dimensional quantum field theories (FQFT). A key feature of this approach is the absence of ultraviolet divergences. We show that, nevertheless, in the FQFT…

Mathematical Physics · Physics 2025-10-07 Maxim Gritskov , Andrey Losev

We consider the inverse problem for the wave equation which consists of determining an unknown space-dependent force function acting on a vibrating structure from Cauchy boundary data. Since only boundary data are used as measurements, the…

Numerical Analysis · Mathematics 2014-10-24 S. O. Hussein , D. Lesnic

We study the classical and quantum models of a flat Friedmann-Robertson-Walker (FRW) space-time, coupled to a perfect fluid, in the context of the consensus and a gauge-fixed Lagrangian frameworks. It is shown that, either in the usual or…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Babak Vakili

We have discovered long-lived waves in two sets of numerical models of fast (marginally bound or unbound) flyby galaxy collisions, carried out independently with two different codes. In neither simulation set are the spirals the result of a…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-16 Curtis Struck , Clare L. Dobbs , Jeong-Sun Hwang

Variational (Rayleigh-Ritz) methods are applied to local quantum field theory. For scalar theories the wave functional is parametrized in the form of a superposition of Gaussians and the expectation value of the Hamiltonian is expressed in…

High Energy Physics - Theory · Physics 2016-08-25 George Tiktopoulos

A classical computation of gravitational bremsstrahlung in ultra-planckian collisions of massive point particles is presented in an arbitrary number d of toroidal or non-compact extra dimensions. Our method generalizes the post-linear…

High Energy Physics - Theory · Physics 2015-06-11 Dmitry Gal'tsov , Pavel Spirin , Theodore N. Tomaras

The fully-implicit time discretization (i.e. the backward Euler formula) is applied to compressible nonlinear dynamical models of thermo-viscoelastic solids in the Eulerian description, i.e. in the actual deforming configuration, formulated…

Numerical Analysis · Mathematics 2025-12-09 Tomáš Roubíček

Buoyancy-induced (Rayleigh-Benard) convection of a fluid between two horizontal plates is a central paradigm for studying the transition to complex spatiotemporal dynamics in sustained nonequilibrium systems. To improve the analysis of…

Pattern Formation and Solitons · Physics 2007-05-23 M. C. Lai , K. H. Chiam , M. C. Cross , H. S. Greenside

We extend the investigation of the structure of the late-time wavefunction of the universe to a class of toy models of scalars with time-dependent masses and polynomial couplings, which contains general massive scalars in FRW cosmologies.…

High Energy Physics - Theory · Physics 2019-09-06 Paolo Benincasa

The Liouville-Lanczos approach to linear-response time-dependent density-functional theory is generalized so as to encompass electron energy-loss and inelastic X-ray scattering spectroscopies in periodic solids. The computation of virtual…

Materials Science · Physics 2015-06-16 Iurii Timrov , Nathalie Vast , Ralph Gebauer , Stefano Baroni

We derive a time-dependent density functional theory appropriate for calculating the near-edge X-ray absorption spectrum in molecules and condensed matter. The basic assumption is to increase the space of many-body wave functions from one…

Strongly Correlated Electrons · Physics 2015-06-16 G. F. Bertsch , A. Lee

We study the spatio-temporal two-point correlation function of passively advected scalar fields in the inertial-convective range in three dimensions by means of numerical simulations. We show that at small time delays $t$ the correlations…

Working with perturbations about an FLRW spacetime, we compute the gauge-invariant curvature perturbation to second order solely in terms of scalar field fluctuations. Using the curvature perturbation on uniform density hypersurfaces as our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Adam J. Christopherson , Ellie Nalson , Karim A. Malik

We establish the Lagrangian nature of the discrete isospectral and isomonodromic dynamical systems corresponding to the re-factorization transformations of the rational matrix functions on the Riemann sphere. Specifically, in the…

Mathematical Physics · Physics 2013-02-14 Anton Dzhamay

Functional evolution equations are used in the modeling of numerous physical processes. In this work, our main tool is perturbation theory of strongly continuous semigroups. The advantage of this technique is that one can provide functional…

Functional Analysis · Mathematics 2022-06-28 Ismail T. Huseynov , Nazim I. Mahmudov