118619293
Hosotani model in closed-string theory
The Hosotani mechanism (1983) in the closed-string theory with current algebra symmetry is described by the (old covariant) operator method. The author compares the gauge symmetry breaking mechanism in a string theory which contains SU(2) symmetry originated from current algebra with the one in an equivalent compactified closed-string theory. The author also investigates the difference between the Hosotani mechanism and the Higgs mechanism in closed-string theories by calculation of a four-point amplitude of 'Higgs' bosons at tree level.
118536921
Quantum Corrections to Scattering Amplitude in Conical Space-time
It is known that the vacuum polarization of zero-point field arises around a conical singularity generated by an infinite, straight cosmic string. In this paper we study quantum electromagnetic corrections to the gravitational Aharonov-Bohm effect around a cosmic string. We find the scattering amplitude from a conical defect for charged Klein-Gordon field.
118693225
GAUGE FIELDS ON TORUS AND PARTITION FUNCTION OF STRINGS
In this paper we consider the interrelation between compactified string theories on torus and gauge fields on it. We start from open string theories with background gauge fields and derive partition functions by path integral. Since the effects of background fields and compactification correlate only through string zero modes, we investigate these zero modes. From this point of view, we discuss the Wilson loop mechanism at finite temperature. For the closed string, only a few comments are mentioned.
118007215
On the cosmology of Weyl's gauge invariant gravity
Recently the vector inflation has been proposed as the alternative to inflationary models based on scalar bosons and quintessence scalar fields. In the vector inflationary model, the vector field non-minimally couples to gravity. We should, however, inquire if there exists a relevant fundamental theory which supports the inflationary scenario. We investigate the possibility that Weyl's gauge gravity theory could be such a fundamental theory. That is the reason why the Weyl's gauge invariant vector and scalar fields are naturally introduced. After rescaling the Weyl's gauge invariant Lagrangian to the Einstein frame, we find that in four dimensions the Lagrangian is equivalent to Einstein-Proca theory and does not have the vector field non-minimally coupled to gravity, but has the scalar boson with a polynomial potential which leads to the spontaneously symmetry breakdown.
118476788
Hosotani mechanism in higher dimensional Lee-Wick theory
Hosotani mechanism in higher-dimensional Lee-Wick theory is investigated. The symmetry breaking mechanism proposed by Hosotani is studied at one-loop level through a toy model in this theory. We find that the phase diagram of symmetry and masses of fields are modified from the original one if masses of Lee-Wick particles are in the same order of the inverse of the compactification scale.
53378499
Classical and quantum cosmology of multigravity
Recently, a multigraviton theory on a simple closed circuit graph corresponding to the discretization of S1 compactification of the Kaluza–Klein (KK) theory has been considered. In the present paper, we extend this theory to that on a general graph and study what modes of particles are included. Furthermore, we generalize it in a possible nonlinear theory based on the vierbein formalism and study classical and quantum cosmological solutions in the theory. We found that scale factors in a solution for this theory repeat acceleration and deceleration.
118234841
Super-kamiokande atmospheric neutrino analysis of matter-dependent neutrino oscillation models