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相关论文: Primordial Fluctuations within Teleparallelism

200 篇论文

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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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 $f$,…

广义相对论与量子宇宙学 · 物理学 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…

天体物理学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

高能物理 - 理论 · 物理学 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…

宇宙学与河外天体物理 · 物理学 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…

高能物理 - 理论 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

广义相对论与量子宇宙学 · 物理学 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…

宇宙学与河外天体物理 · 物理学 2024-06-04 Cristian Joana