English
Related papers

Related papers: The Cosmological Trajectories Method: Modelling co…

200 papers

Thermal Sunyaev-Zel'dovich effect is one of the recent probes of cosmology and large scale structures. We update constraints on cosmological parameters from galaxy clusters observed by the Planck satellite in a first attempt to combine…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Laura Salvati , Marian Douspis , Nabila Aghanim

The power spectrum of density fluctuations is a foundational source of cosmological information. Precision cosmological probes targeted primarily at investigations of dark energy require accurate theoretical determinations of the power…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-26 Katrin Heitmann , David Higdon , Martin White , Salman Habib , Brian J. Williams , Christian Wagner

We consider the space-time-matter theory (STM) in a five-dimensional vacuum space-time with a generalized FLRW metric to investigate the late-time acceleration of the universe. For this purpose, we derive the four-dimensional induced field…

General Relativity and Quantum Cosmology · Physics 2019-08-20 Raziyeh Zaregonbadi

We present a new approach to describe statistics of the non-linear matter density field that exploits a degeneracy in the impact of different cosmological parameters on the linear dimensionless matter power spectrum, $\Delta^2_{\rm L}(k)$.…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-29 Ariel G. Sanchez , Andrés N. Ruiz , Jenny Gonzalez Jara , Nelson D. Padilla

Perturbation theory is a powerful tool for studying large-scale structure formation in the universe and calculating observables such as the power spectrum or bispectrum. However, beyond linear order, typically this is done by assuming a…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-09 Nicholas Choustikov , Zvonimir Vlah , Anthony Challinor

The standard $\Lambda$CDM model can be mimicked at the background and perturbative levels (linear and non-linear) by a class of gravitationally induced particle production cosmology dubbed CCDM cosmology. However, the radiation component in…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-14 I. Baranov , J. F. Jesus , J. A. S. Lima

The Zeldovich approximation is applied to study the accretion of hot and cold dark matter onto moving long strings. It is assumed that such defects carry a substantial amount of small-scale structure, thereby acting gravitationally as a…

Astrophysics · Physics 2009-12-30 V. Zanchin , J. A. S. Lima , R. Brandenberger

Understanding the large-scale structure of the universe remains a fundamental challenge in cosmology, with computational simulations providing critical insights into non-linear structure growth. Particularly, computational simulations…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-12 Nitish Yadav

We present an expression for the nonlinear evolution of the cosmological power spectrum based on following Lagrangian trajectories. This is simplified using the Zel'dovich approximation to trace particle displacements, assuming Gaussian…

Astrophysics · Physics 2015-06-24 A. N. Taylor , A. J. S. Hamilton

We derive non-relativistic equations of motion for the formation of cosmological structure in a Scalar Field Dark Matter (SFDM) model corresponding to a complex scalar field endowed with a quadratic scalar potential. Starting with the full…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-29 L. Arturo Urena-Lopez

According to the separate universe conjecture, spherically symmetric sub-regions in an isotropic universe behave like mini-universes with their own cosmological parameters. This is an excellent approximation in both Newtonian and general…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-14 Gábor Rácz , László Dobos , Róbert Beck , István Szapudi , István Csabai

Cosmological $N$-body simulations are the standard tool to study the emergence of the observed large-scale structure of the Universe. Such simulations usually solve for the gravitational dynamics of matter within the Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-24 Jacob Brandbyge , Cornelius Rampf , Thomas Tram , Florent Leclercq , Christian Fidler , Steen Hannestad

We report the findings of new exact analytical solutions to the cosmological fluid equations, namely for the case where the initial conditions are perturbatively close to a spherical top-hat profile. To do so we enable a fluid description…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-28 Cornelius Rampf

Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the high-precision measurements of galaxy power spectrum, when combined with cosmic microwave background (CMB) information. In this paper we…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 Shun Saito , Masahiro Takada , Atsushi Taruya

We propose an alternative, nonsingular, cosmic scenario based on gravitationally induced particle production. The model is an attempt to evade the coincidence and cosmological constant problems of the standard model ($\Lambda$CDM) and also…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 J. A. S. Lima , S. Basilakos , F. E. M. Costa

The Newtonian Lagrangian perturbation theory is a widely used framework to study structure formation in cosmology in the nonlinear regime. We review a general-relativistic formulation of such a perturbation approach, emphasizing results on…

General Relativity and Quantum Cosmology · Physics 2022-11-10 Thomas Buchert , Ismael Delgado Gaspar , Jan J. Ostrowski

The post-Newtonian (PN) perturbative framework has been successful in understanding the slow-motion, weak field limit of Einstein's theory of gravity on solar system scales, and for isolated astrophysical systems. The parameterized…

General Relativity and Quantum Cosmology · Physics 2017-10-11 Viraj A. A. Sanghai

We investigate the cosmological implications of non-polynomial quasi-topological gravity (NPQTG), a novel class of modified gravitational theories in which the background dynamics is encoded in a single function of the Hubble parameter.…

General Relativity and Quantum Cosmology · Physics 2026-04-15 Emmanuel N. Saridakis

We develop a new approach to building cosmological models, in which small pieces of perturbed Minkowski space are joined together at reflection-symmetric boundaries in order to form a global, dynamical space-time. Each piece of this…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Viraj A. A. Sanghai , Timothy Clifton

Non-minimally coupled f(R) gravity model is an interesting approach to explain the late time acceleration of the Universe without introducing any exotic matter component in the energy budget of the Universe. But distinguishing such model…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-25 Shruti Thakur , Anjan A Sen