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Related papers: Inflation on a Non-Commutative Space-Time

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Noncommutative geometry can provide effective description of physics at very short distances taking into account generic effects of quantum gravity. Inflation amplifies tiny quantum fluctuations in the early universe to macroscopic scales…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-18 Tomi S. Koivisto , David F. Mota

In this article we consider the bounds on the noncommutative nature of space-time. We argue that these bounds are extremely model dependent. In the only phenomenologically viable framework, i.e. when the fields are taken to be in the…

High Energy Physics - Phenomenology · Physics 2011-09-13 Xavier Calmet

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

Following an elegant approach that merge the effects of the stringy spacetime uncertainty relation into primordial perturbations suggested by Brandenberger and Ho, we show the mode equation up to the first order of non-commutative…

High Energy Physics - Theory · Physics 2009-11-10 Dao-jun Liu , Xin-zhou Li

We briefly discuss some possible cosmological implications of noncommutative geometry. While the noncommutativity we consider does not affect gravity, it can play an important role in the dynamics of other fields that are present in the…

High Energy Physics - Theory · Physics 2009-10-31 Chong-Sun Chu , Brian R. Greene , Gary Shiu

The power spectra of the scalar and tensor perturbations in the noncommutative k-inflation model are calculated in this paper. In this model, all the modes created when the stringy space-time uncertainty relation is satisfied are generated…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-11 Chao-Jun Feng , Xin-Zhou Li , Dao-Jun Liu

Inflation as the leading paradigm depicting the very early universe physics could leave imprints on the cosmic microwave background (CMB) radiation. Using currently available CMB observations, we give the tightest constraints on inflation…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-30 Deng Wang

We study a model of power-law inflationary inflation using the Space-Time-Matter (STM) theory of gravity for a five dimensional (5D) canonical metric that describes an apparent vacuum. In this approach the expansion is governed by a single…

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

We argue that the emergent spacetime picture admits a background-independent formulation of cosmic inflation. The inflation in this picture corresponds to the dynamical emergence of spacetime while the conventional inflation is simply an…

High Energy Physics - Theory · Physics 2019-02-27 Hyun Seok Yang

Many inflating spacetimes are likely to violate the weak energy condition, a key assumption of singularity theorems. Here we offer a simple kinematical argument, requiring no energy condition, that a cosmological model which is inflating --…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Arvind Borde , Alan H. Guth , Alexander Vilenkin

We propose a model for cosmic inflation which is based on an effective description of strongly interacting, nonsupersymmetric matter within the framework of dynamical abelian projection and centerization. The underlying gauge symmetry is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Hofmann , Mathias Th. Keil

Noncommutative inflation is based upon the consideration of some effects of the space-time uncertainty principle motivated by ideas from string/M theory. The CMB anisotropies may carry a signature of this very early Universe correction from…

Astrophysics · Physics 2009-11-11 Xin Zhang , Feng-Quan Wu

Using the fact that we only observe those modes which exit the Hubble horizon during inflation, one can calculate the entanglement entropy of such long-wavelength perturbations by tracing out unobservable sub-Hubble fluctuations they are…

High Energy Physics - Theory · Physics 2022-06-14 Suddhasattwa Brahma

We investigate how the uncertainty of noncommutative spacetime affects on inflation. For this purpose, the noncommutative parameter $\mu_0$ is taken to be a zeroth order slow-roll parameter. We calculate the noncommutative power spectrum up…

High Energy Physics - Theory · Physics 2009-11-10 Hungsoo Kim , Gil Sang Lee , Hyung Won Lee , Yun Soo Myung

Non-commutative geometry indicates a deformation of the energy-momentum dispersion relation $f(E)\equiv\frac{E}{pc}(\neq 1)$ for massless particles. This distorted energy-momentum relation can affect the radiation dominated phase of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-27 U. D. Machado , R. Opher

We consider a universe in which inflation commences because of a positive cosmological constant, the effect of which is progressively screened by the interaction between virtual gravitons that become trapped in the expansion of spacetime.…

High Energy Physics - Phenomenology · Physics 2009-10-30 N. C. Tsamis , R. P. Woodard

A scale-invariant universe can have a period of accelerated expansion at early times: inflation. We use a frame-invariant approach to calculate inflationary observables in a scale invariant theory of gravity involving two scalar fields -…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-26 Pedro G. Ferreira , Christopher T. Hill , Johannes Noller , Graham G. Ross

We develop our recent suggestion that inflation may be made past eternal, so that there is no initial cosmological singularity or "beginning of time". Inflation with multiple vacua generically approaches a steady-state statistical…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Anthony Aguirre , Steven Gratton

We show how a radiation dominated universe subject to space-time quantization may give rise to inflation as the radiation temperature exceeds the Planck temperature. We consider dispersion relations with a maximal momentum (i.e. a mimimum…

High Energy Physics - Theory · Physics 2009-11-07 Stephon Alexander , Robert Brandenberger , Joao Magueijo

The existence of the inflationary era in the early Universe seems to be strongly supported by recent CMB observations. However, only a few realistic inflation scenarios which have close relation to particle physics seem to have been known…

High Energy Physics - Phenomenology · Physics 2015-01-05 Romy H. S. Budhi , Shoichi Kashiwase , Daijiro Suematsu