7,263 research outputs found
On Induced Gravity in 2-d Topological Theories
We study 2-d gauge theories with the objective to understand, also
at the quantum level, the emergence of induced gravity. The wave functionals -
representing the eigenstates of a vanishing flat potential - are obtained in
the representation. The composition of the space they describe is then
analyzed: the state corresponding to the singlet representation of the gauge
group describes a topological universe. For other representations a metric
which is invariant under the residual gauge group is induced, apart from
possible topological obstructions. Being inherited from the group metric it is
rather rigid.Comment: 38, tex, 160/93/e
Towards a tensionless string field theory for the N=(2,0) CFT in d=6
We describe progress in using the field theory of tensionless strings to
arrive at a Lagrangian for the six-dimensional conformal
theory. We construct the free part of the theory and propose an ansatz for the
cubic vertex in light-cone superspace. By requiring closure of the
supersymmetry algebra, we fix the cubic vertex up to two parameters.Comment: 46 pages, 2 figures. V2: references added; minor changes and
improvement
Lifting SU(2) Spin Networks to Projected Spin Networks
Projected spin network states are the canonical basis of quantum states of
geometry for the most recent EPR-FK spinfoam models for quantum gravity. They
are functionals of both the Lorentz connection and the time normal field. We
analyze in details the map from these projected spin networks to the standard
SU(2) spin networks of loop quantum gravity. We show that this map is not
one-to-one and that the corresponding ambiguity is parameterized by the Immirzi
parameter. We conclude with a comparison of the scalar products between
projected spin networks and SU(2) spin network states.Comment: 14 page
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