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Related papers: Primordial Fluctuations within Teleparallelism

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In this Letter we consider a general quadratic parity-preserving theory for a general flat connection. Imposing a local symmetry under the general linear group singles out the general teleparallel equivalent of General Relativity carrying…

General Relativity and Quantum Cosmology · Physics 2020-04-22 Jose Beltrán Jiménez , Lavinia Heisenberg , Damianos Iosifidis , Alejandro Jiménez-Cano , Tomi S. Koivisto

We construct a theory in which the gravitational interaction is described only by torsion, but that generalizes the Teleparallel Theory still keeping the invariance of local Lorentz transformations in one particular case. We show that our…

General Relativity and Quantum Cosmology · Physics 2016-07-07 Ednaldo L. B. Junior , Manuel E. Rodrigues

Teleparallel gravity theories were proposed as alternatives to the dark energy and modified theories of gravity. However, both the metric and symmetric teleparallel gravity theories have been found to have serious pathologies, such as…

General Relativity and Quantum Cosmology · Physics 2024-07-16 Dalia Saha , Jyoti Prasad Saha , Abhik kumar sanyal

A field kinetic coupling with the Einstein tensor leads to a gravitationally enhanced friction during inflation, by which even steep potentials with theoretically natural model parameters can drive cosmic acceleration. In the presence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Shinji Tsujikawa

We investigate a bounce inflation model with a graceful exit into the Friedmann-Robertson-Walker (FRW) decelerated Universe within $f(T)$ gravity framework, where $T$ is the torsion scalar in the teleparallelism. We study the cosmic thermal…

General Relativity and Quantum Cosmology · Physics 2016-10-13 Kazuharu Bamba , G. G. L. Nashed , W. El Hanafy , Sh. K. Ibraheem

Symmetric Teleparallel Gravity is an exceptional theory of gravity that is consistent with the vanishing affine connection. This theory is an alternative and a simpler geometrical formulation of general relativity, where the non-metricity…

General Relativity and Quantum Cosmology · Physics 2021-07-23 Sanjay Mandal , N. Myrzakulov , P. K. Sahoo , R. Myrzakulov

Cosmological inflation remains a key paradigm for explaining the earliest stages of the Universe, yet the theoretical limitations of General Relativity (GR) motivate the development of alternative formulations capable of addressing both…

General Relativity and Quantum Cosmology · Physics 2025-11-13 Maryam Shiravand , Saeed Fakhry , Javad T. Firouzjaee , Ali Tizfahm

We consider modified teleparallel gravity, (f(T) gravity), as a framework to explain the present accelerated expansion of the universe. The matter component is assumed to be cold dark matter. To find the explicit form of the function $f$,…

General Relativity and Quantum Cosmology · Physics 2015-06-11 H. Mohseni Sadjadi

We develop a general formalism for analyzing linear perturbations in multiple-field cosmological inflation based on the gauge-ready approach. Our inflationary model consists of an arbitrary number of scalar fields with non-minimal kinetic…

Astrophysics · Physics 2009-11-13 Joydev Lahiri , Gautam Bhattacharya

In this paper, we study inflation in the framework of the nonrelativistic general covariant theory of the Ho\v{r}ava-Lifshitz gravity with the projectability condition and an arbitrary coupling constant $\lambda$. We find that the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Yongqing Huang , Anzhong Wang , Qiang Wu

We investigate the cosmological perturbations in generalized gravity, where the Ricci scalar and a scalar field are non-minimally coupled via an arbitrary function. In the Friedmann-Lemaitre-Robertson-Walker background, by studying the…

High Energy Physics - Theory · Physics 2009-07-30 Xiangdong Ji , Tower Wang

Supersolid inflation is a class of inflationary theories that simultaneously breaks time and space reparameterization invariance during inflation, with distinctive features for the dynamics of cosmological fluctuations. We investigate…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Angelo Ricciardone , Gianmassimo Tasinato

Due to the quasi-exponential red-shifting which occurs during an inflationary period in the very early Universe, wavelengths which at the present time correspond to cosmological lengths are in general sub-Planckian during the early stages…

High Energy Physics - Theory · Physics 2017-08-23 Robert H. Brandenberger

In previous works, questioning the mathematical nature of the connection in the translations gauge theory formulation of Teleparallel Equivalent to General Relativity (TEGR) Theory led us to propose a new formulation using a Cartan…

General Relativity and Quantum Cosmology · Physics 2021-10-06 E. Huguet , M. Le Delliou , M. Fontanini

The geometry of parallelizable manifolds (i.e., teleparallelism) is summarized in the language of local frame fields. Some problems in continuum mechanics that relate to the couple-stresses that are produced in the bending and twisting of…

General Relativity and Quantum Cosmology · Physics 2013-05-16 D. H. Delphenich

We revisit an extension of the well-known formalism for gauge-invariant scalar metric fluctuations, to study the spectrums for both, the inflaton and gauge invariant (scalar) metric fluctuations in the framework of a single field…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Mariano Anabitarte , Mauricio Bellini

For most initial conditions, cosmologically relevant physical modes were trans-planckian at the bounce time, often by many magnitude orders. We improve the usual loop quantum cosmology calculation of the primordial power spectra -- in the…

General Relativity and Quantum Cosmology · Physics 2018-05-23 Killian Martineau , Aurélien Barrau , Julien Grain

We investigate the cosmological perturbations around all three branches of spatially flat universe with different connections in symmetric teleparallel gravity. The model we consider can cover both the case of f(Q) model and that of the…

General Relativity and Quantum Cosmology · Physics 2023-12-06 Haomin Rao , Chunhui Liu , Chao-Qiang Geng

We investigate the evolution of scalar perturbations in $f(T)$ teleparallel gravity and its effects on the cosmic microwave background (CMB) anisotropy. The $f(T)$ gravity generalizes the teleparallel gravity which is formulated on the…

General Relativity and Quantum Cosmology · Physics 2018-05-22 Rafael C. Nunes

We investigate the initiation of cosmic inflation, in full numerical relativity, from pre-inflationary scenarios with large tensor and vector fluctuations in the metric. These settings are characterized by having large values in the Weyl…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-04 Cristian Joana