28025238
Dirac quantization in superspace.
We extend the method of Dirac quantization to superspace. We study simple models like the supersymmetric quantum mechanics as well as the supersymmetric nonlinear \ensuremath{\sigma} model in 1+1 dimensions. Although in both these cases the matrix representing the Poisson brackets between the constraints is singular, we show, following the spirit of Dirac, that one can still define Dirac brackets and that the resulting quantization is consistent with those of the component fields.
119439378
Continuum limit of supersymmetric field theories on a lattice
The ground-state energy density E/sub 0/ is examined for a wide class of two-dimensional supersymmetric quantum field theories by use of a strong-coupling lattice expansion. It is shown that regardless of how the lattice expansion is defined (there are many ways to put the fermions on the lattice) E/sub 0/..-->..0 in the continuum limit.
16176875
The algebra of flat currents for the string on AdS5 × S5 in the light-cone gauge
We continue the program initiated in [41] and calculate the algebra of the flat currents for the string on AdS5 × S5 background in the light-cone gauge with κ symmetry fixed. We find that the algebra has a closed form and that the non-ultralocal terms come with a weight factor e(σ) that depends on the radial AdS5 coordinate. Based on results in two-dimensional sigma models coupled to gravity via the dilaton field, this suggests that the algebra of transition matrices in the present case is likely to be unambigous.
9495818
ON M-THEORY AND THE SYMMETRIES OF TYPE II STRING EFFECTIVE ACTIONS
We study the “ordinary” Scherk-Schwarz dimensional reduction of the bosonic sector of the low energy effective action of a hypothetical M-theory on S1 × S1 ≊ T2. We thus obtain the low energy effective actions of type IIA string theory in both ten and nine space-time dimensions. We point out how to obtain the O(1,1) invariance of the NS-NS sector of the string effective action correctly in nine dimensions. We dimensionally reduce the type IIB string effective action on S1 and show that the resulting nine-dimensional theory can be mapped, purely from the bosonic consideration, exactly to the type IIA theory by an O(1,1) or Buscher's T-duality transformations. We then give a dynamical argument, in analogy with that for the type IIB theory in ten dimensions, to show how an S-duality in the type IIA theory can be understood from the underlying nine-dimensional theory by compactifying M-theory on a T-dual torus T2.
120503298
Systematic expansion for compact QED near weak coupling
121912240
Chiral Schwinger model in curved space-time
We extend the method of path integrals to obtain the solution of the chiral Schwinger model in curved space-time and compare it with the flat space-time solution.
1360767
Electromagnetic and gravitational scattering at Planckian energies.
The scattering of pointlike particles at very large center-of-mass energies and fixed low momentum transfers, occurring due to both their electromagnetic and gravitational interactions, is reexamined in the particular case when one of the particles carries a magnetic charge. At Planckian center-of-mass energies, when gravitational dominance is usually expected, the presence of a magnetic charge is shown to produce dramatic modifications to the scattering cross section as well as to the holomorphic structure of the scattering amplitude.