N. D. Hari Dass

Residual supersymmetry of compactified d = 10 supergravity

Abstract The conditions for residual supersymmetry in compactified ten-dimensional supergravity theories are investigated, including the effect of a non-constant “warp factor”. The analysis is based on on-shell transformation laws which implies that certain linear combinations of classical field equations must be satisfied. The conditions for supersymmetry are, in general, not very restrictive. When, in addition, one assumes the validity of Bianchi identities, two independent contractions of the Einstein equation are implied. These equations exclude d = 4 de Sitter space; for compactifications to d = 4 Minkowski space they only allow purely metric Ricci-flat field configurations with constant warp factor.

Parity violating Compton amplitude in unified theories

The leading contribution of O (

On the QCD effective action for pions and vector mesons

alpha

Simplified method for trace anomaly calculations in d{<=}6

G/sub F/) to the parity violating piece of the electron Compton amplitude is calculated in the Weinberg Salam unified theory and is shown to vanish. The reason for this is the nonexistence of parity violating charge and electric dipole moment. In the computation, a problem with the usual gauge fixing terms in the Weinberg model was encountered and resolved; the gauge fixing terms made it impossible to satisfy the electromagnetic Ward identity off mass-shell. The resolution of this problem has led to changed Feynman rules resulting in fewer graphs and gauge dependent vertices. Further features are a renormalization of the parity violating infinities, and a discussion of how the

On the details of the variational investigations of SU(2) euclidean lattice gauge theories

gamma

Calculation of parity violating part of the compton amplitude

sub 5

Axial anomaly and Ginsparg-Wilson fermions in the lattice Dirac sea picture

-algebra and n-dimensional regularization can coexist peacefully. (AIP)

Photon decay into neutrinos in a strong magnetic field

Abstract The effective action for pions and π, A 1 and ω vector mesons is discussed with the generating functional for QCD as a starting point and including the anomalous terms that originate from the axial anomaly. The effective action is coupled to the weak-electromagnetic sector of the standard model and its experimental consequences are discussed.

Gravitational two-body problem—A source theory viewpoint

We discuss a simplified method for computing trace anomalies in dimensions d{<=}6. It is known that in the quantum mechanical approach trace anomalies in d dimensions are given by a (d/2+1)-loop computation in an auxiliary 1D sigma model with arbitrary geometry. We show how one can obtain the same information using a simpler (d/2)-loop calculation on an arbitrary geometry supplemented by a (d/2+1)-loop calculation on the simplified geometry of a maximally symmetric space.