247 citations · 268 across the 7 of their papers we have counts for
9 papers
Relic Neutrinos Probing Small Scale Primordial Non-Gaussianity
Suraj Gavhale, Shin'ichi Nojiri, Sergei D. Odintsov +1
Relic neutrinos retain a record of electromagnetic entropy production after neutrino decoupling, probing primordial modes erased from the primary CMB. We derive the cubic photon nu…
Cosmological Perturbation in New General Relativity: Propagating mode from the violation of local Lorentz invariance
Kyosuke Tomonari, Taishi Katsuragawa, Shin'ichi Nojiri
We investigate the propagating modes of New General Relativity (NGR) in second-order linear perturbations in the Lagrangian density (first-order in field equations). The Dirac-Berg…
Revisiting Coincident GR in Internal STEGR Formulation
Kyosuke Tomonari, Taishi Katsuragawa, Shin'ichi Nojiri
We revisit Coincident General Relativity (CGR) in the gauge approach to gravity based on Symmetric Teleparallel Equivalent to General Relativity (STEGR) in the \textit{internal-spa…
Compact star in noninteger power model of gravity
Yong-Xiang Cui, Zu Yan, Kota Numajiri +2
We investigate compact stars in the noninteger power (NIP) model of gravity theory, which includes the higher-curvature correction to the Einstein-Hilbert action. The mass-r…
Future singularity in an anisotropic universe
Taishi Katsuragawa, Shin'ichi Nojiri, Sergei D. Odintsov
We investigate future singularities originating from the anisotropy in the Universe. We formulate a new class of singularities in the homogeneous and anisotropic universe, comparin…
Theoretical and observational constraints on early dark energy in gravity
Hua Chen, Taishi Katsuragawa, Shin'ichi Nojiri +1
This work examines an early dark energy (EDE) scenario in the context of gravity. EDE is introduced to alleviate the Hubble tension by temporarily injecting approximately $1…
Nonpropagating ghost in covariant gravity
Kun Hu, Makishi Yamakoshi, Taishi Katsuragawa +2
gravity is an extension of the symmetric teleparallel equivalent to general relativity (STEGR). This work shows that based on the scalar-nonmetricity formulation, a scalar m…
Viscous Little Rip Cosmology
I. Brevik, E. Elizalde, S. Nojiri +1
Dark energy of phantom or quintessence nature with an equation of state parameter almost equal to -1 often leads the universe evolution to a finite-time future singularity. An…
Vacuum energy fluctuations, the induced cosmological constant and cosmological reconstruction in non-minimal modified gravity models
G. Cognola, E. Elizalde, S. Nojiri +1
The one-loop effective action for non-minimal scalar modified gravity on de Sitter background with a constant scalar field is found. The corresponding induced cosmological constant…