English
Related papers

Related papers: Integrated perturbation theory for cosmological te…

200 papers

In a class of non-singular cosmologies derived from higher-order corrections to the low-energy bosonic string action, we derive evolution equations for the most general cosmological scalar, vector and tensor perturbations. In the large…

Astrophysics · Physics 2009-11-06 Cyril Cartier , Jai-chan Hwang , Edmund J. Copeland

By using the thermodynamic theory of irreversible processes and Einstein general relativity, a cosmological model is proposed where the early universe is considered as a mixture of a scalar field with a matter field. The scalar field refers…

General Relativity and Quantum Cosmology · Physics 2009-11-07 G. M. Kremer , F. P. Devecchi

We consider cosmology in the Einstein-aether theory (the generally covariant theory of gravitation coupled to a dynamical timelike Lorentz-violating vector field) with a linear aether-Lagrangian. The 3+1 spacetime splitting approach is used…

Astrophysics · Physics 2008-11-26 Baojiu Li , David F. Mota , John D. Barrow

In almost all structure formation models, primordial perturbations are created within a homogeneous and isotropic universe, like the one we observe. Because their ensemble averages inherit the symmetries of the spacetime in which they are…

Astrophysics · Physics 2009-06-23 C. Armendariz-Picon

In this review, we summarize the main ideas of perturbative algebraic quantum field theory, which is a rigorous framework combining some of the Haag-Kastler axioms with perturbative methods involving formal power series. It allows for the…

Mathematical Physics · Physics 2025-12-17 Romeo Brunetti , Klaus Fredenhagen , Kasia Rejzner

We study an ensemble of random matrices (the Rosenzweig-Porter model) which, in contrast to the standard Gaussian ensemble, is not invariant under changes of basis. We show that a rather complete understanding of its level correlations can…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Alexander Altland , Martin Janssen , Boris Shapiro

The matter density field exhibits a nearly lognormal probability density distribution (PDF) after entering into the nonlinear regime. Recently, it has been shown that the shape of the power spectrum of a logarithmically transformed density…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Xin Wang , Mark Neyrinck , István Szapudi , Alex Szalay , Xuelei Chen , Julien Lesgourgues , Antonio Riotto , Martin Sloth

One of the most interesting directions in theoretical high-energy and condensed-matter physics is understanding dynamical properties of collective states of quantum field theories. The most elementary tool in this quest is retarded…

High Energy Physics - Theory · Physics 2020-08-27 Mari Carmen Banuls , Michal P. Heller , Karl Jansen , Johannes Knaute , Viktor Svensson

Kinetic Field Theory (KFT) is a statistical field theory for an ensemble of point-like classical particles in or out of equilibrium. We review its application to cosmological structure formation. Beginning with the construction of the…

A new gauge-invariant approach for describing cosmological perturbations is developed. It is based on a physically motivated splitting of the stress-energy tensor of the perturbation into two parts - the bare perturbation and the…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Sergei M. Kopeikin , Juan Ramirez , Bahram Mashhoon , Mikhail V. Sazhin

A physical field has an infinite number of degrees of freedom since it has a field value at each location of a continuous space. Therefore, it is impossible to know a field from finite measurements alone and prior information on the field…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-12 Torsten A. Enßlin

We examine the capabilities of the modified perturbation theory (MPT) for description of $W$-pair production and decay in $e^{+} e^{-}$ annihilation. In a model with Dyson-resummed propagators of unstable particles, we calculate even and…

High Energy Physics - Phenomenology · Physics 2021-01-25 M. L. Nekrasov

The conventional weak-coupling expansion for the pressure of a hot plasma shows no sign of convergence unless the the coupling constant $g$ is tiny. In this talk, I discuss screened perturbation theory (SPT) which is a reorganization of the…

High Energy Physics - Phenomenology · Physics 2017-08-23 Jens O. Andersen

We develop a new approach to Vlasov Perturbation Theory (VPT) that solves for the hierarchy of cumulants of the phase-space distribution function to arbitrarily high truncation order in the context of cosmological structure formation driven…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-03 Mathias Garny , Roman Scoccimarro

The tensor-train (TT) format is a data-sparse tensor representation commonly used in high dimensional data approximations. In order to represent data with interpretability in data science, researchers develop data-centric skeletonized low…

Numerical Analysis · Mathematics 2026-02-10 Daniel Hayes , Jing-Mei Qiu , Tianyi Shi

Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Claes Uggla , John Wainwright

The effects of three-dimensional perturbations in two-dimensional turbulence are investigated, through a conformal field theory approach. We compute scaling exponents for the energy spectra of enstrophy and energy cascades, in a strong…

High Energy Physics - Theory · Physics 2009-10-28 L. Moriconi

The connection between ghost-free formulations of RG-invariant perturbation theory in the both Euclidean and Minkowskian regions is studied. Our basic tool is the "double spectral representation", similar to definition of Adler function,…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. V. Shirkov

As put forward in [arXiv:1907.12339] topological quantum field theories can be projected using so-called projection defects. The projected theory and its correlation functions can be completely realized within the unprojected one. An…

High Energy Physics - Theory · Physics 2021-04-07 Fabian Klos , Daniel Roggenkamp

Integrated Information Theory is one of the leading models of consciousness. It aims to describe both the quality and quantity of the conscious experience of a physical system, such as the brain, in a particular state. In this contribution,…

Neurons and Cognition · Quantitative Biology 2020-02-19 Johannes Kleiner , Sean Tull