Scalar field theories on the world sheet: cutoff independent treatment

BPH Renormalization of Cutoff Scalar Field

We show that general cutoff scalar field theories in four dimensions are perturbatively renormalizable through the use of diagrammatic techniques and an adapted BPH renormalization method. Weinberg's convergence theorem is used to show that operators in the Lagrangian with dimension greater than four, which are divided by powers of the cutoff, produce perturbatively only local divergences in th...

A geometric approach to scalar field theories on the supersphere

Following a strictly geometric approach we construct globally supersymmetric scalar field theories on the supersphere, defined as the quotient space S = UOSp(1|2)/U(1). We analyze the superspace geometry of the supersphere, in particular deriving the invariant vielbein and spin connection from a generalization of the left-invariant Maurer-Cartan form for Lie groups. Using this information we pr...

Infrared Properties of Scalar Field Theories

scalar-tensor theories for traceless matter field

ω(φ) → ∞ limit of scalar tensor theories are studied for traceless matter source. It is shown that the limit ω(φ) → ∞ does not reduce a scalar tensor theory to GR. An exact radiation solution of scalar tensor cosmology under modified Nordtvedt conditions is obtained for flat Friedmann universe. PACS numbers: 04.50. +h

Quantum Field Theories on Manifolds with Curved Boundaries: Scalar Fields

A framework allowing for perturbative calculations to be carried out for quantum field theories with arbitrary smoothly curved boundaries is described. It is based on an expansion of the Green function for second order differential operators valid in the neighbourhood of the boundary and which is obtained from a corresponding expansion of of the associated heat kernel derived earlier for arbitr...