1,981 research outputs found
On the Passage from the Quantum theory to the Semi-Classical theory
In this paper an attempt is made to understand the passage from the exact
quantum treatment of the CGHS theory to the semi-classical physics discussed by
many authors. We find first that to the order of accuracy to which Hawking
effects are calculated in the theory, it is inconsistent to ignore correlations
in the dilaton gravity sector. Next the standard Dirac or BRST procedure for
implementing the constraints is followed. This leads to a set of physical
states, in which however the semi-classical physics of the theory seems to be
completely obscured. As an alternative, we construct a coherent state
formalism, which is the natural framework for understanding the semi-classical
calculations, and argue that it satisfies all necessary requirements of the
theory, provided that there exist classical ghost configurations which solve an
infinite set of equations. If this is the case it may be interpreted as a
spontaneous breakdown of general covariance.Comment: 19 pages, COLO-HEP-31
On Integrating Out Heavy Fields in SUSY Theories
We examine the procedure for integrating out heavy fields in supersymmetric
(both global and local) theories. We find that the usual conditions need to be
modified in general and we discuss the restrictions under which they are valid.
These issues are relevant for recent work in string compactification with
fluxes.Comment: Typos corrected, minor changes. 10 page
Anomaly cancellation in M-theory
We show the complete cancellation of gauge and gravitational anomalies in the
M-theory of Horava and Witten using their boundary contribution, and a term
coming from the existence of two and five-branes. A factor of three discrepancy
noted in an earlier work is resolved. We end with a comment on flux
quantization.Comment: 5 pages, Latex, typos corrected, minor notation change in eq. (0.7).
Version to be published in Phys. Lett.
A Unified Approach to Supersymmetry Breaking
General formulae for the soft SUSY breaking terms, valid in any SUGRA
context, were derived in the mid-nineties. Since SUSY is not expected to have
quantum anomalies, they should be valid in the quantum theory and be RG
invariant down to the soft SUSY breaking scale. This observation enables us to
give a uniform treatment of all phenomenological models for SUSY breaking and
transmission, such as AMSB, GMSB, etc. In particular we find that the much
discussed RG invariant formulae for soft SUSY breaking parameters in AMSB,
effectively depend on a strong assumption of factorizability of the matter
Kaehler metric. We then argue that there is no necessity for having ad hoc
constructions such as mAMSB to counteract the negative squared slepton mass
problem, since the natural framework that emerges in a sequestered model is one
in which gaugino masses are as in AMSB, and the other soft terms are generated
by RG running as in gaugino mediation.Comment: 13 page
Black Hole Physics from Liouville Theory
In a previous paper it was shown that the quantum consistency conditions for
the dilaton-gravity theory of Callan et al., imply that the cosmological
constant term undergoes a dilaton dependent renormalization, in such a manner
that the theory can be written as a Liouville-like theory. In this paper we
discuss the physical interpretation of the solutions of this theory. In
particular we demonstrate explicitly how quantum corrections tame the black
hole singularity. Also under the assumption that in asymptotically Minkowski
coordinates, there are no incoming or outgoing ghosts, we show that the Hawking
radiation rate is independent of the number of matter fields and is determined
by the ghost conformal anomaly.Comment: 15 pages, phyzzx (Note on Bondi mass added to end of paper
Examining Gender Stereotypes in New Work/Family Reconciliation Policies: The Creation of a New Paradigm for Egalitarian Legislation
The 2011 symposium: The Changing Face of Families, will focus on the evolution of assisted reproductive technologies, and its effects on traditional legal notions of marriage, parent, and family
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