ar X iv : h ep - p h / 93 02 25 1 v 1 1 1 Fe b 19 93

ar X iv : h ep - p h / 93 02 25 4 v 1 1 2 Fe b 19 93 BROWN - HET - 896 February 1993 Gamma Ray Bursts From Ordinary Cosmic Strings

We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective a...

ar X iv : h ep - t h / 93 02 11 6 v 1 2 4 Fe b 19 93 AHARONOV - BOHM SCATTERING , CONTACT INTERACTIONS AND SCALE INVARIANCE

We perform a perturbative analysis of the Aharonov-Bohm problem to one loop in a field-theoretic formulation, and show that contact interactions are necessary for renormalizability. In general, the classical scale invariance of this problem is broken quantum mechanically. There exists however a critical point for which this anomaly disappears.

ar X iv : h ep - p h / 04 02 19 0 v 1 1 8 Fe b 20 04 1 Pentaquarks in the 10 F - and 10 F - plets

ar X iv : h ep - p h / 98 02 41 9 v 1 2 5 Fe b 19 98 COURSE LARGE N QCD

ar X iv : h ep - t h / 93 02 04 3 v 1 1 1 Fe b 19 93 ON THE HOPF ALGEBRAS GENERATED BY THE YANG - BAXTER R - MATRICES

We reformulate the method recently proposed for constructing quasitriangular Hopf algebras of the quantum-double type from the R-matrices obeying the Yang-Baxter equations. Underlying algebraic structures of the method are elucidated and an illustration of its facilities is given. The latter produces an example of a new quasitriangular Hopf algebra. The corresponding universal R-matrix is prese...