Zobrazeno 1 - 10
of 25
pro vyhledávání: '"Tsuyuki, Takanao"'
Autor:
Sato, Yuichiro, Tsuyuki, Takanao
We study time-dependent compactification of extra dimensions. We assume that the spacetime is spatially homogeneous, and solve the vacuum Einstein equations without cosmological constant in more than three dimensions. We consider globally hyperbolic
Externí odkaz:
http://arxiv.org/abs/2304.10193
Publikováno v:
Phys. Rev. D 107 (2023) 9, 095039
We study the generation number of massless fermions in compactifications recently found in heterotic supergravity. The internal spaces are products of two-dimensional spaces of constant curvature, and the standard embedding is not assumed. The genera
Externí odkaz:
http://arxiv.org/abs/2303.09872
Publikováno v:
Phys.Rev.D 108 (2023) 5, 055002
We show that three open questions in particle physics and cosmology: the origin of neutrino mass, the identity of dark matter, and the origin of the baryon asymmetry of the universe can be explained simultaneously in the three-loop seesaw model propo
Externí odkaz:
http://arxiv.org/abs/2211.10059
Publikováno v:
Phys. Rev. D 105, 095018 (2022)
We study the lepton flavor violating decays such as $\mu\to e\gamma$, $\tau\to e\gamma$, $\tau\to \mu\gamma$ in the three-loop radiative seesaw model proposed by Krauss, Nasri, and Trodden. In this model, the relevant coupling constants are larger fo
Externí odkaz:
http://arxiv.org/abs/2202.00931
Autor:
Tsuyuki, Takanao
Publikováno v:
Phys. Rev. D 104, 066009 (2021)
We compactify the ten-dimensional spacetime in heterotic supergravity leaving four-dimensional Minkowski spacetime. We search for nonsupersymmetric, non-Ricci-flat solutions of the equations of motion with the quadratic curvature term. By assuming th
Externí odkaz:
http://arxiv.org/abs/2106.03625
Autor:
Asaka, Takehiko, Tsuyuki, Takanao
Publikováno v:
Phys. Lett. B (2016) 147-149
We consider the Standard Model extended by right-handed neutrinos to explain massive neutrinos through the seesaw mechanism. The new fermion can be observed when it has a sufficiently small mass and large mixings to left-handed neutrinos. If such a p
Externí odkaz:
http://arxiv.org/abs/1509.02678
Autor:
Asaka, Takehiko, Tsuyuki, Takanao
Publikováno v:
Phys. Rev. D 92, 094012 (2015)
We consider the Standard Model with right-handed neutrinos to explain the masses of active neutrinos by the seesaw mechanism. Since active neutrinos as well as heavy neutral leptons are Majorana fermions in this case, the lepton number violating proc
Externí odkaz:
http://arxiv.org/abs/1508.04937
Autor:
Tsuyuki, Takanao
Publikováno v:
Phys. Rev. D 91, 076004 (2015)
By using quark Yukawa matrices only, we can construct renormalization invariants that are exact at the one-loop level in the standard model. One of them $I^q$ is accidentally consistent with unity, even though quark masses are strongly hierarchical.
Externí odkaz:
http://arxiv.org/abs/1501.07785
Autor:
Tsuyuki, Takanao
We show that Yukawa couplings of bottom quarks and tau leptons can be unified in a non-supersymmetric SU(5) model. We introduce an arbitrary number of right-handed neutrinos. Their masses and Yukawa couplings that satisfy the unification condition by
Externí odkaz:
http://arxiv.org/abs/1411.2769
Autor:
Tsuyuki, Takanao
Publikováno v:
Phys. Rev. D 90, 013007 (2014)
We analyze a scenario in which the lightest heavy neutrino $N_1$ is a dark matter candidate and the second- heaviest neutrino $N_2$ decays producing a lepton number. If $N_1$ were in thermal equilibrium, its energy density today would be much larger
Externí odkaz:
http://arxiv.org/abs/1403.5053