1,277 research outputs found
Group Averaging and Refined Algebraic Quantization
We review the framework of Refined Algebraic Quantization and the method of
Group Averaging for quantizing systems with first-class constraints. Aspects
and results concerning the generality, limitations, and uniqueness of these
methods are discussed.Comment: 4 pages, LaTeX 2.09 using espcrc2.sty. To appear in the proceedings
of the third "Meeting on Constrained Dynamics and Quantum Gravity", Nucl.
Phys. B (Proc. Suppl.
The Past, puzzles, and promise of 6-branes
The fact that both the D6-brane and the orientifold 6-plane have smooth,
horizon-free descriptions in M-theory makes them especially useful in
understanding certain aspects of brane physics. We briefly review how this
connection has been used to understand a number of effects, several of which
are associated with the Hanany-Witten transition. One particular outcome is a
"confinement mod 2" effect for zero-branes in the background of a single
D8-brane. We also discuss an interesting puzzle associated with flux-expulsion
from D6-branes in this context. Finally, we discuss the promise of using a
similar M-theoretic description of the orientifold 6-plane to understand the
consistency of stringy negative energy objects with the 2nd law of black hole
thermodynamics.Comment: Contribution to the proceedings of the 10th Tohwa International
Symposium, Fukuoka, Japan, July 3-7, 2001. 12 pages, 1 figur
Emergent Gravity requires (kinematic) non-locality
This work refines arguments forbidding non-linear dynamical gravity from
appearing in the low energy effective description of field theories with local
kinematics, even for those with instantaneous long-range interactions.
Specifically, we note that gravitational theories with universal coupling to
energy -- an intrinsically non-linear phenomenon -- are characterized by
Hamiltonians that are pure boundary terms on shell. In order for this to be the
low energy effective description of a field theory with local kinematics, all
bulk dynamics must be frozen and thus irrelevant to the construction. The
result applies to theories defined either on a lattice or in the continuum, and
requires neither Lorentz-invariance nor translation-invariance.Comment: 7 pages + title page & reference
The Black Hole information problem: past, present, and future
We give a brief overview of the black hole information problem emphasizing
fundamental issues and recent proposals for its resolution. The focus is on
broad perspective and providing a guide to current literature rather than
presenting full details. We concentrate on resolutions restoring naive
unitarity.Comment: Key Issues Review for Reports on Progress of Physics, 20 pages, minor
change
On Group Averaging for SO(n,1)
The technique known as group averaging provides powerful machinery for the
study of constrained systems. However, it is likely to be well defined only in
a limited set of cases. Here, we investigate the possibility of using a
`renormalized' group averaging in certain models. The results of our study may
indicate a general connection between superselection sectors and the rate of
divergence of the group averaging integral.Comment: Minor corrections, 17 pages,RevTe
The Spectral Analysis Inner Product for Quantum Gravity
This submission to the Proceedings of the Seventh Marcel-Grossman Conference
is an advertisement for the use of the ``spectral analysis inner product" for
minisuperspace models in quantum gravity.Comment: 5 pages LaTex, UCSBTH-94-38, CGPG-94/9-
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