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We present a coherent, re-usable python framework which further builds on the cosmological emulator code CosmoPower. In the current era of high-precision cosmology, we require high-accuracy calculations of cosmological observables with…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 H. T. Jense , I. Harrison , E. Calabrese , A. Spurio Mancini , B. Bolliet , J. Dunkley , J. C. Hill

We investigate cosmological scenarios with spin-gravity coupling. In particular, due to the spin of the baryonic and dark matter particles and its coupling to gravity, they probe an effective spin-dependent metric, which can be calculated…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Giovanni Otalora , Emmanuel N. Saridakis

We study the cosmological constraints on the variation of the Newton's constant and on post-Newtonian parameters for simple models of scalar-tensor theory of gravity beyond the extended Jordan-Brans-Dicke theory. We restrict ourselves to an…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-07 M. Rossi , M. Ballardini , M. Braglia , F. Finelli , D. Paoletti , A. A. Starobinsky , C. Umiltà

We discuss a field-theoretical approach based on variational principle to derive the field and hydrodynamic equations of motion of baryonic matter governed by cosmological perturbations of dark matter and dark energy. The action depends on…

General Relativity and Quantum Cosmology · Physics 2015-01-27 Sergei M. Kopeikin , Alexander N. Petrov

We consider the perturbation dynamics for the cosmic baryon fluid and determine the corresponding power spectrum for a $\Lambda(t)$CDM model in which a cosmological term decays into dark matter linearly with the Hubble rate. The model is…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-30 R. F. vom Marttens , W. S. Hipólito-Ricaldi , W. Zimdahl

Linear cosmological observables can be used to probe elastic scattering of dark matter (DM) with baryons. Availability of high-precision data requires a critical reassessment of any assumptions that may impact the accuracy of constraints.…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-02 Suroor Seher Gandhi , Yacine Ali-Haïmoud

We have developed a torsion balance with a sensitivity about ten times better than those of previously operating balances for the study of long range forces coupling to baryon and lepton number. We present here the details of the design and…

General Relativity and Quantum Cosmology · Physics 2021-07-07 Ramanath Cowsik , Dawson Huth , Tsitsi Madziwa-Nussinov

In this paper we introduce a new public Einstein-Boltzmann solver, \texttt{MGCLASS II}, built as a modification to the publicly available \texttt{CLASS} code, that allows to obtain cosmological observables for Modified Gravity theories. It…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-28 Ziad Sakr , Matteo Martinelli

We present a scenario in which a scalar field dark energy is coupled to the trace of the energy momentum tensor of the baryonic matter fields. In the slow-roll regime, this interaction could give rise to the cosmological features of dark…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-02 Alejandro Aviles , Jorge L. Cervantes-Cota

We study the cosmology of a quadratic metric-compatible torsionful gravity theory in the presence of a perfect hyperfluid. The gravitational action is an extension of the Einstein-Cartan theory given by the usual Einstein-Hilbert…

General Relativity and Quantum Cosmology · Physics 2021-10-07 Damianos Iosifidis , Lucrezia Ravera

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

This Thesis concentrates on the analysis of coupled RTA (relaxation time approximation) kinetic equations for bosons and fermions. Bosons are treated as massless particles, while fermions have a finite mass. Using analytic and numerical…

Nuclear Theory · Physics 2019-07-04 Ewa Maksymiuk

We present a fully relativistic calculation of the matter bispectrum at second order in cosmological perturbation theory assuming a Gaussian primordial curvature perturbation. For the first time we perform a full numerical integration of…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-26 Thomas Tram , Christian Fidler , Robert Crittenden , Kazuya Koyama , Guido W. Pettinari , David Wands

We demonstrate that baryonification algorithms, which displace particles in gravity-only simulations according to physically-motivated prescriptions, can simultaneously capture the impact of baryonic physics on the 2 and 3-point statistics…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Giovanni Aricò , Raul E. Angulo , Carlos Hernández-Monteagudo , Sergio Contreras , Matteo Zennaro

In a previous work we obtained a set of necessary conditions for the linear approximation in cosmology. Here we discuss the relations of this approach with the so called covariant perturbations. It is often argued in the literature that one…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-04 S. D. P. Vitenti , F. T. Falciano , N. Pinto-Neto

The expansion rate of the Universe deviates from its standard value when the total energy density includes contribution from a new scalar field apart from the radiation energy density. The non-trivial modifications incurred in the Boltzmann…

High Energy Physics - Phenomenology · Physics 2022-11-29 Mainak Chakraborty , Sourov Roy

Standard cosmological models rely on an approximate treatment of gravity, utilizing solutions of the linearized Einstein equations as well as physical approximations. In an era of precision cosmology, we should ask: are these approximate…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-06 John T. Giblin , James B. Mertens , Glenn D. Starkman , Chi Tian

As one of the possible extensions of Einstein's General Theory of Relativity, it has been recently suggested that the presence of spacetime torsion could solve problems of the very early and the late-time universe undergoing accelerating…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-19 Tonghua Liu , Ziqiang Liu , Jiamin Wang , Shengnan Gong , Man Li , Shuo Cao

In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for…

Computational Physics · Physics 2016-02-17 E. Ilseven , M. Mendoza

In this work, building up on [1] we present momentum space Ward identities related to broken higher spin symmetry as an alternate approach to computing correlators of spinning operators in interacting theories such as the quasi-fermionic…

High Energy Physics - Theory · Physics 2021-07-28 Sachin Jain , Renjan Rajan John , Vinay Malvimat