1,287 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
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-
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
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