• Corpus ID: 248377537

Stronger gravity in the early universe

  title={Stronger gravity in the early universe},
Scalar-tensor theories of gravity that embrace conformal coupling to the scalar curvature are the focal point of cosmology on discussions of inflation and late-time accelerating universe. Although there exists a stringent nucleo-synthesis constraint on conformal gravity, one can formulate how to evade this difficulty by modifying the standard particle theory action consistently with the principles of gauge invariant quantum field theory. It is shown that stronger gravity at early epochs of… 

B-L genesis by sliding inflaton

  • M. Yoshimura
  • Physics
    Journal of Cosmology and Astroparticle Physics
  • 2022
We propose a new mechanism of lepton (L) number asymmetry generation, hence offer an explanation of matter-antimatter imbalance when a significant amount of baryon number is later transformed from

Modified propagation of gravitational waves from the early radiation era

We study the propagation of cosmological gravitational wave (GW) backgrounds from the early radiation era until the present day in modified theories of gravity. Comparing to general relativity (GR),

Dynamical relaxation of cosmological constant

A special class of conformal gravity theories is proposed to solve the long standing problem of the fine-tuned cosmological constant. In the proposed model time evolution of the inflaton field leaves

Unity of cosmological inflation attractors.

The aim of this Letter is to elucidate the common denominator of these attractors: their robust predictions stem from a joint pole of order 2 in the kinetic term of the inflaton field in the Einstein frame formulation prior to switching to the canonical variables.

Accelerating universe and the time-dependent fine-structure constant

  • Y. Fujii
  • Physics
    Proceedings of the International Astronomical Union
  • 2009
I start with assuming a gravitational scalar field as the dark-energy supposed to be responsible for the accelerating universe. Also from the point of view of unification, a scalar field implies a

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LIGO Scientific Collaboration and Virgo Collaboration

  • Phys. Rev. Lett. 119,
  • 2017

Cosmological evolution is analyzed in a theory of Jordan - Brans - Dicke type that introduces a constant cosmological constant alone without inflaton dependent potential in the Jordan frame

  • 2007


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