3,994 research outputs found

### Smeared heat-kernel coefficients on the ball and generalized cone

We consider smeared zeta functions and heat-kernel coefficients on the
bounded, generalized cone in arbitrary dimensions. The specific case of a ball
is analysed in detail and used to restrict the form of the heat-kernel
coefficients $A_n$ on smooth manifolds with boundary. Supplemented by conformal
transformation techniques, it is used to provide an effective scheme for the
calculation of the $A_n$. As an application, the complete $A_{5/2}$ coefficient
is given.Comment: 23 pages, JyTe

### The $a_{3/2}$ heat kernel coefficient for oblique boundary conditions

We present a method for the calculation of the $a_{3/2}$ heat kernel
coefficient of the heat operator trace for a partial differential operator of
Laplace type on a compact Riemannian manifold with oblique boundary conditions.
Using special case evaluations, restrictions are put on the general form of the
coefficients, which, supplemented by conformal transformation techniques,
allows the entire smeared coefficient to be determined.Comment: 30 pages, LaTe

### Heat-kernel coefficients for oblique boundary conditions

We calculate the heat-kernel coefficients, up to $a_2$, for a U(1) bundle on
the 4-Ball for boundary conditions which are such that the normal derivative of
the field at the boundary is related to a first-order operator in boundary
derivatives acting on the field. The results are used to place restrictions on
the general forms of the coefficients. In the specific case considered, there
can be a breakdown of ellipticity.Comment: 9 pages, JyTeX. One reference added and minor corrections mad

### Gauge-Averaging Functionals for Euclidean Maxwell Theory in the Presence of Boundaries

This paper studies the one-loop expansion of the amplitudes of
electromagnetism about flat Euclidean backgrounds bounded by a 3-sphere,
recently considered in perturbative quantum cosmology, by using zeta-function
regularization. For a specific choice of gauge-averaging functional, the
contributions to the full zeta value owed to physical degrees of freedom,
decoupled gauge mode, coupled gauge modes and Faddeev-Popov ghost field are
derived in detail, and alternative choices for such a functional are also
studied. This analysis enables one to get a better understanding of different
quantization techniques for gauge fields and gravitation in the presence of
boundaries.Comment: 41 pages, plain-tex, recently appearing in Classical and Quantum
Gravity, volume 11, pages 905-926, April 1994. The author wants to apologize
for the delay in circulating the file, due to technical problems now fixe

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