119274633
BORN-INFELD MONOPOLES AND INSTANTONS
We show that in certain non-Abelian Born-Infeld-Higgs theories there are monopole solutions obeying Bogomol’nyi-like equations in the PrasadSommerfield limit. We also discuss the existence of instanton solution in an SU(2) Born-Infeld theory. Upon a spontaneous breaking of gauge symmetry containing the SO(3) group, topologically stable configurations of gauge and scalar fields, known as “monopoles” may form [1]. The properties of the nonsingular objects, such as their masses, charges, and spins, have been closely investigated from the point of view of testing the grand unineation scheme. Besides the phenomenological characteristics, nathenatical methods for constructing the general monopole configurations have also been studied with much interest. The most interesting feature is the Bogomol’nyi equations [2] in the Prasad-Sommerfield limit [3]. The study of the Bogomol’nyi equations give not only the bound for monopole mass limit also the proof of existence of multi-monopole solutions [4]. The interaction among monopoles is very simplified when the Bogomol’nyi equations hold [5]. The first-order equations is also intimately related to study of supersymmetric systems [6]. Recently, the possibility that Yang-Mills interactions may receive correction at high energy region has been argued along with studying the string theory [7]. As a candidate for the modification, a generalized Born-Infeld (BI) action [8] instead of Yang-Mills action is preferred in effective field theories of open string theory [9]. The generalized-BI theory is expected to yield good behavior of its classical solution and wave propagation similarly to the original BI theory [10]. In our previous paper, we offered generalized (Abelian) Born-Infeld models in which there are self-dual vortex solutions [11]. In the present paper, we
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.
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.
102352448
Exact solutions for gravitational collapse with a dilaton field in arbitrary dimensions
We present time-dependent analytic solutions to the Einstein equations coupled with a dilaton (scalar) field. The background geometry for the solutions is a product of an N-dimensional spherically symmetric space and a d-dimensional flat space. We discuss the global properties of the spacetime.
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.
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.
118234841
Super-kamiokande atmospheric neutrino analysis of matter-dependent neutrino oscillation models