18067993
Critical boundary sine-Gordon revisited
Abstract We revisit the exact solution of the two space-time dimensional quantum field theory of a free massless boson with a periodic boundary interaction and self-dual period. We analyze the model by using a mapping to free fermions with a boundary mass term originally suggested in Ref. [J. Polchinski, L. Thorlacius, Phys. Rev. D 50 (1994) 622]. We find that the entire SL (2, C) family of boundary states of a single boson are boundary sine-Gordon states and we derive a simple explicit expression for the boundary state in fermion variables and as a function of sine-Gordon coupling constants. We use this expression to compute the partition function. We observe that the solution of the model has a strong–weak coupling generalization of T-duality. We then examine a class of recently discovered conformal boundary states for compact bosons with radii which are rational numbers times the self-dual radius. These have simple expression in fermion variables. We postulate sine-Gordon-like field theories with discrete gauge symmetries for which they are the appropriate boundary states.
117114158
Relativistic Anyon and (2+1) Dimensional Gravity
18394193
Topological Ward identity and anti-de Sitter space / CFT correspondence
Abstract The dual relationship between the supergravity in the anti-de Sitter (AdS) space and the superconformal field theory is discussed in the simplest form. We show that a topological Ward identity holds in the three dimensional Chern–Simons gravity. In this simple case the proposed dual relationship can be understood as the topological Ward identity. Extensions to the supersymmetric theories and higher dimensional ones are also briefly discussed.
119401888
Tachyon condensation, boundary state, and noncommutative solitons
We discuss tachyon condensation in a single unstable D-brane in the framework of the boundary state formulation. The boundary state in the background of tachyon condensation and the Neveu-Schwarz B-field is explicitly constructed. We show in both commutative theory and noncommutative theory that the unstable D-branes behave like an extended object and eventually reduce to lower dimensional D-branes as the system approaches the infrared fixed point. We clarify the relationship between the commutative field theoretical description of tachyon condensation and the noncommutative one.
56316687
Quantum Brownian Motion on a Triangular Lattice and Fermi-Bose Equivalence: An Application of Boundary State Formulation
We discuss the Bose-Fermi equivalence in the quantum Brownian motion (QBM) on a triangular lattice, mapping the action for the QBM into a string theory action with a periodic boundary tachyon potential. We construct new Klein factors which are more appropriate than the conventional ones to deal with the quantum field theories defined on a two dimensioanl space-time with boundaries. Using the Fermi-Bose equivalence with the new Klein factors, we show that the model for the quantum Bownian motion on a triangular lattice is equivalent to the Thirring model with boundary terms, which are quadratic in fermion field operators, in the off-critical regions and to a SU(3) × SU(3) free fermion theory with quadratic boundary terms at the critical point.
118937531
Discrete light cone quantization of anti-de Sitter black hole and black string
117932598
Longitudinal Z boson pair production via gluon fusion in technicolor models
We study the coupling of two longitudinal Z-bosons to two gluons via technicolor interactions. Noticing a similarity of this process to $2 \gamma \rightarrow 2 \pi^{0}$, we calculate the amplitude in chiral perturbation theory in one-generation technicolor model. At the invariant mass of $ Z_{L}Z_{L}$ above the colored pseudo-Goldstone boson threshold, we find the signal in proton collisions at $\sqrt{s} = 14\, TeV$ is stronger than the standard model background by an order of magnitude, and is large enough to be easily observable at LHC. 
The cross section for $W_{L}^{+}W_{L}^{-}$ pair production is also presented.
118567299
Gravitino as a Sterile Neutrino
A scheme is described in which the light gravitino in low energy SUSY breaking models mixes with neutrinos. The mixing between gravitino and neutrinos arises through the standard model symmetry breaking and an R-parity and lepton number violating bilinear term in the superpotential. It is shown that mixings compatible with the neutrino experiments can be obtained within the cosmological bound on the bilinear term set by the baryon asymmetry of the universe.
119331109
Perturbative Calculation of the Anomalous Decay Rate in Dense Matter
119360577
Neutrino clustering in the galaxy with a global monopole
In spherically symmetric, static spacetime, we show that only j=1/2 fermions can satisfy both Einstein's field equation and Dirac's equation. It is also shown that neutrinos are able to have effective masses and cluster in the galactic halo when they are coupled to a global monopole situated at the galactic core. Astronomical implications of the results are discussed.
18619603
Heavy fermion production and the symmetry breaking sector of the electroweak interactions
Abstract We point out that heavy fermion production through the fusion of the longitudinal gauge bosons might be relevant in probing the strongly interacting symmetry breaking sector of the electroweak interactions, by showing the dependence of the one loop amplitude for ( w + w − → t t ) on the symmetry breaking mechanism. The one loop amplitude for ( w + w − → t t ) is calculated for the standard model and extended technicolour theory. Techni-rho meson exchange is also briefly discussed. We find that at m t =150 GeV the cross section of top pair production in e + e − collisions is comparable in order of magnitude to that of the longitudinal gauge boson scattering.