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Related papers: Non-Extensive Entropy and Power-Law Inflation: Imp…

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We have presented previously a general treatment of Starobinsky-like inflation in no-scale supergravity where the tensor-to-scalar ratio $r = 3(1 - n_s)^2$, and $n_s$ is the tilt of the scalar perturbations. In particular, we have shown how…

High Energy Physics - Theory · Physics 2019-10-02 John Ellis , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner

Recent evidences of stochastic gravitational wave background (SGWB) through Pulsar Time Array (PTA) observations hint towards an alternative inflationary scenario, compared to the usual inflation, for describing the early stage of the…

General Relativity and Quantum Cosmology · Physics 2026-02-02 Simone D'Onofrio , Sergei Odintsov , Tanmoy Paul

We show that it is possible to combine an early phase of String Gas Cosmology which can explain the origin of the observed structures on cosmological scales with a short later period of power law inflation which creates spatial flatness.…

High Energy Physics - Theory · Physics 2020-05-20 Vahid Kamali , Robert Brandenberger

Inflation elegantly provides initial conditions for the standard model of cosmology, while solving the horizon, flatness, and magnetic monopole problems. Inflationary models make predictions for the tensor-to-scalar ratio $r$ and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 L. Balkenhol , E. Camphuis , F. Finelli , K. Benabed , F. R. Bouchet , J. Carron , S. Galli , E. Hivon , A. R. Khalife , L. Knox , C. L. Reichardt , A. Vitrier , W. L. K. Wu

We investigate two classes of non-minimally coupled curvature-matter models in the FLRW universe with a perfect fluid and analyze their cosmological implications using Supernova Ia, Observed Hubble Data, and Baryon Acoustic Oscillation…

General Relativity and Quantum Cosmology · Physics 2024-12-31 Anirban Chatterjee , Akshay Panda , Abhijit Bandyopadhyay

A recent paper argued that it is not possible to infer the energy scale of inflation from the amplitude of tensor fluctuations in the Cosmic Microwave Background, because the usual connection is substantially altered if there are a large…

High Energy Physics - Theory · Physics 2016-01-20 Matthew Kleban , Mehrdad Mirbabayi , Massimo Porrati

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

In the framework of inflation, scales which nowadays correspond to large scale structures were smaller than the Planck length at the beginning of inflation. Therefore, measurements of CMBR anisotropy or surveys of galaxies and of clusters…

Astrophysics · Physics 2007-05-23 Jerome Martin , Robert H. Brandenberger

The FRW model with non-minimally coupled massive scalar field has been investigated in LQC framework. Considered form of the potential and coupling allows applications to Higgs driven inflation. Out of two frames used in the literature to…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Michal Artymowski , Andrea Dapor , Tomasz Pawlowski

Quintessential inflation provides a unified description of the early and late accelerated phases of the Universe, linking the inflationary epoch to the present-day dark energy-dominated era through a single scalar degree of freedom. In this…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-25 Jamerson Rodrigues , Gabriel Rodrigues , Felipe B. M. dos Santos , Simony Santos da Costa , Jailson Alcaniz

We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat $\Lambda$CDM model. Unlike…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama

We compute the spectrum of cosmological perturbations in a scenario in which inflation is driven by radiation in a non-commutative space-time. In this scenario, the non-commutativity of space and time leads to a modified dispersion relation…

High Energy Physics - Theory · Physics 2010-10-27 Seoktae Koh , Robert H. Brandenberger

We investigate the cosmological inflation in a class of supergravity models that are generalizations of non-supersymmetric $R^2$ models. Although such models have been extensively studied recently, especially after the launch of the PLANCK…

High Energy Physics - Theory · Physics 2015-06-23 G. A. Diamandis , B. C. Georgalas , K. Kaskavelis , P. Kouroumalou , A. B. Lahanas , G. Pavlopoulos

It was shown by Tsallis and Cirto that thermodynamical entropy of a gravitational system such as black hole must be generalized to the non-additive entropy, which is given by $S_h=\gamma A^{\beta}$, where $A$ is the horizon area and $\beta$…

General Relativity and Quantum Cosmology · Physics 2018-09-26 Ahmad Sheykhi

We study how the noncommutative spacetime affects on inflation. First we obtain the noncommutative power spectrum of the curvature perturbations produced during inflation in the slow-roll approximation. This is the explicit $k$-dependent…

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

For a robust interpretation of upcoming observations from PLANCK and LHC experiments it is imperative to understand how the inflationary dynamics of a non-minimally coupled Higgs scalar field with gravity may affect the determination of the…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-27 L. A. Popa , A. Caramete

In the standard Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model, the energy conditions provides model-independent bounds on the behavior of the distance modulus. However, this method can not provide us the detailed information…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Wen-Fei Liu , Jing Niu , Juan Li , Tong-Jie Zhang

The nonextensive statistics based on Tsallis entropy have been so far used for the systems composed of subsystems having same $q$. The applicability of this statistics to the systems with different $q$'s is still a matter of investigation.…

Statistical Mechanics · Physics 2007-05-23 Qiuping A. Wang

We investigate how the non-extensive approach works in high-energy physics. Transverse momentum ($p_T$) spectra of several hadrons are fitted by various non-extensive momentum distributions and by the Boltzmann--Gibbs statistics.~It is…

High Energy Physics - Phenomenology · Physics 2019-05-23 Keming Shen , Gergely Gábor Barnaföldi , Tamás Sándor Biró

A new inflationary scenario whose exponential potential $V(\Phi)$ has a quadratic dependence on the field $\Phi$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy…

Astrophysics · Physics 2009-06-23 F. C. Carvalho , J. S. Alcaniz , J. A. S. Lima , R. Silva