461 research outputs found
Surface holonomy and gauge 2-group
Just as point objects are parallel transported along curves, giving
holonomies, string-like objects are parallel transported along surfaces, giving
surface holonomies. Composition of these surfaces correspond to products in a
category theoretic generalization of the gauge group, called a 2-group. I
consider two different ways of constructing surface holonomies, one by using a
pair of one and two form connections, and another by using a pair of one-form
connections. Both procedures result in the structure of a 2-group.Comment: 8pp, RevTeX4, Submitted upon invitation to IJGMM
Decay of the Cosmological Constant. Equivalence of Quantum Tunneling and Thermal Activation in Two Spacetime Dimensions
We study the decay of the cosmological constant in two spacetime dimensions
through production of pairs. We show that the same nucleation process looks as
quantum mechanical tunneling (instanton) to one Killing observer and as thermal
activation (thermalon) to another. Thus, we find another striking example of
the deep interplay between gravity, thermodynamics and quantum mechanics which
becomes apparent in presence of horizons.Comment: 11 pages, 6 figure
Electric-Magnetic Black Hole Duality
We generalize duality invariance for the free Maxwell action in an arbitrary
background geometry to include the presence of electric and magnetic charges.
In particular, it follows that the actions of equally charged electric and
magnetic black holes are equal
p-Brane Dyons and Electric-magnetic Duality
We discuss dyons, charge quantization and electric-magnetic duality for
self-interacting, abelian, p-form theories in the spacetime dimensions D=2(p+1)
where dyons can be present. The corresponding quantization conditions and
duality properties are strikingly different depending on whether p is odd or
even. If p is odd one has the familiar eg'-ge'= 2nh, whereas for even p one
finds the opposite relative sign, eg'+ge'= 2nh. These conditions are obtained
by introducing Dirac strings and taking due account of the multiple
connectedness of the configuration space of the strings and the dyons. A
two-potential formulation of the theory that treats the electric and magnetic
sources on the same footing is also given.
Our results hold for arbitrary gauge invariant self-interaction of the fields
and are valid irrespective of their duality properties.Comment: 33 pages, 1 figur
Black Hole Entropy and the Dimensional Continuation of the Gauss-Bonnet Theorem
The Euclidean black hole has topology . It is
shown that -in Einstein's theory- the deficit angle of a cusp at any point in
and the area of the are canonical conjugates. The
black hole entropy emerges as the Euler class of a small disk centered at the
horizon multiplied by the area of the there.These results are
obtained through dimensional continuation of the Gauss-Bonnet theorem. The
extension to the most general action yielding second order field equations for
the metric in any spacetime dimension is given.Comment: 7 pages, RevTe
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