4,352 research outputs found
A Note on the Lower Bound of Black Hole Area Change in Tunneling Formalism
In the framework of tunneling mechanism and employing Bekenstein's general
expression for the variation of the black hole area, we determine the area
quantum up to a constant. Depending on the value of this constant one can get
either Bekenstein's lower bound or Hod's one for the change in the black hole
area.Comment: 4 pages, LaTeX, no figures; v2: 6 pages, clarifications and
references added, no changes in physics and results, to appear in EP
Quantum tunneling and black hole spectroscopy
The entropy-area spectrum of a black hole has been a long-standing and
unsolved problem. Based on a recent methodology introduced by two of the
authors, for the black hole radiation (Hawking effect) as tunneling effect, we
obtain the entropy spectrum of a black hole. In Einstein's gravity, we show
that both entropy and area spectrum are evenly spaced. But in more general
theories (like Einstein-Gauss-Bonnet gravity), although the entropy spectrum is
equispaced, the corresponding area spectrum is not.Comment: 10 pages, LaTeX, no figures; v2: 9 pages, now, title changed, minor
changes to match published version in Phys. Lett.
Dual composition of odd-dimensional models
A general way of interpreting odd dimensional models as a doublet of chiral
models is discussed. Based on the equations of motion this dual composition is
illustrated. Examples from quantum mechanics, field theory and gravity are
considered. Specially the recently advocated topologically massive gravity is
analysed in some details.Comment: minor modification
Connecting anomaly and tunneling methods for Hawking effect through chirality
The role of chirality is discussed in unifying the anomaly and the tunneling
formalisms for deriving the Hawking effect. Using the chirality condition and
starting from the familiar form of the trace anomaly, the chiral
(gravitational) anomaly, manifested as a nonconservation of the stress tensor,
near the horizon of a black hole, is derived. Solution of this equation yields
the stress tensor whose asymptotic infinity limit gives the Hawking flux.
Finally, use of the same chirality condition in the tunneling formalism gives
the Hawking temperature that is compatible with the flux obtained by anomaly
method.Comment: LaTex, 8 pages, no figures, reformulation of tunneling mechanism, to
appear in Phys. Rev.
The Mythology of Game Theory
Non-cooperative game theory is at its heart a theory of cognition, specifically a theory of how decisions are made. Game theory\u27s leverage is that we can design different payoffs, settings, player arrays, action possibilities, and information structures, and that these differences lead to different strategies, outcomes, and equilibria. It is well-known that, in experimental settings, people do not adopt the predicted strategies, outcomes, and equilibria. The standard response to this mismatch of prediction and observation is to add various psychological axioms to the game-theoretic framework. Regardless of the differing specific proposals and results, game theory uniformly makes certain cognitive assumptions that seem rarely to be acknowledged, much less interrogated. Indeed, it is not widely understood that game theory is essentially a cognitive theory. Here, we interrogate those cognitive assumptions. We do more than reject specific predictions from specific games. More broadly, we reject the underlying cognitive model implicitly assumed by game theory
Quantum counter automata
The question of whether quantum real-time one-counter automata (rtQ1CAs) can
outperform their probabilistic counterparts has been open for more than a
decade. We provide an affirmative answer to this question, by demonstrating a
non-context-free language that can be recognized with perfect soundness by a
rtQ1CA. This is the first demonstration of the superiority of a quantum model
to the corresponding classical one in the real-time case with an error bound
less than 1. We also introduce a generalization of the rtQ1CA, the quantum
one-way one-counter automaton (1Q1CA), and show that they too are superior to
the corresponding family of probabilistic machines. For this purpose, we
provide general definitions of these models that reflect the modern approach to
the definition of quantum finite automata, and point out some problems with
previous results. We identify several remaining open problems.Comment: A revised version. 16 pages. A preliminary version of this paper
appeared as A. C. Cem Say, Abuzer Yakary{\i}lmaz, and \c{S}efika
Y\"{u}zsever. Quantum one-way one-counter automata. In R\={u}si\c{n}\v{s}
Freivalds, editor, Randomized and quantum computation, pages 25--34, 2010
(Satellite workshop of MFCS and CSL 2010
Enterprise Responsibility for Personal Injury: Further Reflections
This Article, written by three contributors to the Reporters\u27 Study on Enterprise Responsibility for Personal Injury, offers further reflections about specific areas and proposals in the Study that have evoked important questions and comments. It addresses the concern that there are too many lawyers and lawsuits in the United States, and that it is this overpopulation of lawyers that is causing excessive tort litigation. It also addresses high damage awards and insurance premiums, it recommends refining products liability, and recommends organizational responsibility for medical malpractice. This Article is a supplement to the Study, and offers further examination of important issues raised in the Study
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