4 papers
Inflation and Reheating by Dynamical Torsion
Xiaolin Ma, Kamil Mudrunka, Kazunori Nakayama
In gravity theories with torsion, inflation can be driven by the dynamical torsion. Since it naturally has a derivative coupling to the axial current consisting of Standard Model p…
High Frequency Spectrum of Primordial Gravitational Waves
Kamil Mudrunka, Kazunori Nakayama
During inflation long wavelength gravitational waves are produced, which form stochastic background in the present universe with very wide range of frequencies. Higher frequency gr…
Inflation with Gauss-Bonnet correction: beyond slow-roll
Kamil Mudrunka, Kazunori Nakayama
If a coupling between the inflaton and the Gauss-Bonnet term is introduced, many models of inflation that were ruled out by the most recent Planck data can be made viable again. Th…
Newman-Penrose formalism and exact vacuum solutions to conformal Weyl gravity
Petr Jizba, Kamil MudruÅka
We study the exterior solution for a static, spherically symmetric source in Weyl conformal gravity in terms of the Newman--Penrose formalism. We first show that both the static, u…