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A modification of the action of the general relativity produces a different pattern for the growth of the cosmic structures below a certain length-scale leaving an imprint on the cosmic microwave background (CMB) anisotropies. We re-examine…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-01 Andrea Marchini , Valentina Salvatelli

If the Universe has non-trivial spatial topology, observables depend on both the parameters of the spatial manifold and the position and orientation of the observer. In infinite Euclidean space, most cosmological observables arise from the…

We use growth of structure data to constrain the effective field theory of dark energy. Considering as case study Horndeski theories with the speed of gravitational waves equal to that of light, we show how constraints on the free…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Louis Perenon , Julien Bel , Roy Maartens , Alvaro de la Cruz-Dombriz

If the Universe has non-trivial spatial topology, observables depend on both the parameters of the spatial manifold and the position and orientation of the observer. In infinite Euclidean space, most cosmological observables arise from the…

We use cosmography to present constraints on the kinematics of the Universe without postulating any underlying theoretical model a priori. To this end, we use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova Ia…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

We study Dvali-Gabadadze-Porrati braneworlds with finite thickness. In respect to standard (thin) DGP Friedmann equation, finite thickness of the brane causes a subtle modification of the cosmological equations that can lead to significant…

General Relativity and Quantum Cosmology · Physics 2008-12-10 Israel Quiros , Tonatiuh Matos

Massive bosonic fields can trigger superradiant instabilities in rotating astrophysical black holes leading to gaps in their mass-spin distribution. For spin-2 fields, the instability timescale is orders of magnitude shorter than for any…

High Energy Physics - Theory · Physics 2026-03-12 Bruno Valeixo Bento , Miquel Salicrú Herberg

We investigate cosmological constraints on K-mouflage models of modified gravity. We consider two scenarios: one where the background evolution is free to deviate from $\Lambda$CDM (K-mouflage) and another one which reproduces a…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 Giampaolo Benevento , Marco Raveri , Andrei Lazanu , Nicola Bartolo , Michele Liguori , Philippe Brax , Patrick Valageas

New covariant theories of emergent modified gravity exist not only in spherically symmetric models, as previously found, but also in polarized Gowdy systems that have a local propagating degree of freedom. Several explicit versions are…

General Relativity and Quantum Cosmology · Physics 2024-12-04 Martin Bojowald , Erick I. Duque

Topological structure has been extensively studied and confirmed in highly correlated condensed matter physics. We explore the gravitational waves emitted from binary neutron star mergers using the pseudoconformal model for dense nuclear…

Nuclear Theory · Physics 2021-07-07 Wen-Cong Yang , Yong-Liang Ma , Yue-Liang Wu

The existence of inhomogeneities in the observed Universe modifies the distance-redshift relations thereby affecting the results of cosmological tests in comparison to the ones derived assuming spatially uniform models. By modeling the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 V. C. Busti , R. C. Santos , J. A. S. Lima

Understanding the accelerating expansion of the Universe remains a fundamental challenge in modern cosmology. In this paper, we investigate a cosmological model parametrized by a generalized variable deceleration parameter to elucidate the…

General Relativity and Quantum Cosmology · Physics 2023-09-29 M. Koussour , N. Myrzakulov , Alnadhief H. A. Alfedeel , F. Awad , M. Bennai

Cosmography provides a direct method to map the expansion history of the Universe in a model-independent way. Recently, different kinds of observations have been used in cosmographic analyses, such as SNe Ia and gamma ray bursts…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-06 R. F. L. Holanda , J. S. Alcaniz , J. C. Carvalho

We establish new constraints on $f(T)$ gravity models by using cosmological data. In particular, we investigate the restrictions given by the gas mass fraction measurements of galaxy clusters and transversal BAO data. Both data sets are…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-28 F. B. M. dos Santos , J. E. Gonzalez , R. Silva

A topological constraint on the possible values of the universal quantization parameter is revealed in the case of geometric quantization on (boundary) curves diffeomorphic to $S^1$, analytically extended on a bounded domain in…

Mathematical Physics · Physics 2014-12-25 Razvan Teodorescu

The modified Gauss-Bonnet gravity can be motivated by a number of physical reasons, including: the uniqueness of a gravitational Lagrangian in four and higher dimensions and the leading order $\alpha^\prime$ corrections in superstring…

High Energy Physics - Theory · Physics 2017-08-23 Ishwaree P. Neupane

In this review we present a thoroughly comprehensive survey of recent work on modified theories of gravity and their cosmological consequences. Amongst other things, we cover General Relativity, Scalar-Tensor, Einstein-Aether, and Bimetric…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Timothy Clifton , Pedro G. Ferreira , Antonio Padilla , Constantinos Skordis

Observational data on the large scale structure (LSS) of the Universe are used to establish an upper limit for the amplitude of the tensor mode marginalized over all other cosmological parameters within the class of adiabatic inflationary…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , R. Durrer , S. Apunevych

In this work, we construct the logical framework of the Poincar\'e gauge gravity cosmology based on five postulations, and introduce the modified redshift relation within this framework. Then we solve a system with quadratic action and some…

General Relativity and Quantum Cosmology · Physics 2017-03-03 Hongchao Zhang , Lixin Xu

An approach to estimate the spatial curvature $\Omega_k$ from data independently of dynamical models is suggested, through kinematic parameterizations of the comoving distance ($D_{C}(z)$) with third degree polynomial, of the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-18 J. F. Jesus , R. Valentim , P. H. R. S. Moraes , M. Malheiro
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