1,786 research outputs found
Beyond Indifferent Players: On the Existence of Prisoners Dilemmas in games with amicable and adversarial preferences
Why donât agents cooperate when they both stand to gain? This question ranks among the most fundamental in the social sciences. Explanations abound. Among the most compelling are various configurations of the prisonerâs dilemma (PD), or public goods problem. Payoffs in PDâs are specified in one of two ways: as primitive cardinal payoffs or as ordinal final utility. However, as final utility is objectively unobservable, only the primitive payoff games are ever observed. This paper explores mappings from primitive payoff to utility payoff games and demonstrates that though an observable game is a PD there are broad classes of utility functions for which there exists no associated utility PD. In particular we show that even small amounts of either altruism or enmity may disrupt the mapping from primitive payoff to utility PD. We then examine some implications of these results.
Black Holes with Multiple Charges and the Correspondence Principle
We consider the entropy of near extremal black holes with multiple charges in
the context of the recently proposed correspondence principle of Horowitz and
Polchinski, including black holes with two, three and four Ramond-Ramond
charges. We find that at the matching point the black hole entropy can be
accounted for by massless open strings ending on the D-branes for all cases
except a black hole with four Ramond-Ramond charges, in which case a possible
resolution in terms of brane-antibrane excitations is considered.Comment: 26 pages, harvmac, minor correction
A Correspondence Principle for Black Holes and Strings
For most black holes in string theory, the Schwarzschild radius in string
units decreases as the string coupling is reduced. We formulate a
correspondence principle, which states that (i) when the size of the horizon
drops below the size of a string, the typical black hole state becomes a
typical state of strings and D-branes with the same charges, and (ii) the mass
does not change abruptly during the transition. This provides a statistical
interpretation of black hole entropy. This approach does not yield the
numerical coefficient, but gives the correct dependence on mass and charge in a
wide range of cases, including neutral black holes.Comment: 24 pages, one typo correcte
Multiple Keratoacanthomas, Philadelphia Chromosome+ Acute Lymphoblastic Leukemia, and Dasatinib: A Case Report
Background: Treatment for adult Philadelphia chromosome+ acute lymphoblastic leukemia includes using dasatinib, a tyrosine kinase inhibitor. Cutaneous squamous cell carcinomas and keratoacanthomas are common findings in patients treated with BRAF inhibitors of tyrosine kinases. No documentation of dasatinib inducing multiple keratoacanthomas, squamous cell carcinomas type during treatment of Philadelphia chromosome+ acute lymphoblastic leukemia is currently available. Case: A 77-year-old Caucasian male presented to the dermatology clinic two months after starting treatment with dasatinib for Philadelphia chromosome positive+ acute lymphoblastic leukemia. Biopsies confirmed the lesions on the arms, chest, legs and back as keratoacanthoma (KA) type of squamous cell carcinomas (SCCs). The cutaneous lesions were surgically removed and no new or recurrent lesions were detected since their initial rapid onset despite continued dasatinib therapy. Conclusion: This report of the rapid onset of keratoacanthoma type squamous cell carcinomas in a patient with Philadelphia chromosome+ acute lymphoblastic leukemia treated with dasatinib is presumed to be the first due to the rarity of adult Philadelphia chromosome+ acute lymphoblastic leukemia. This report documents another tyrosine kinase inhibitor that is associated with the eruption of keratoacanthomas, and adds to the literature regarding the regularity of this relatively common side effect, which may have treatment other than surgery if only a few lesions are present
Non-Preemptive Scheduling on Machines with Setup Times
Consider the problem in which n jobs that are classified into k types are to
be scheduled on m identical machines without preemption. A machine requires a
proper setup taking s time units before processing jobs of a given type. The
objective is to minimize the makespan of the resulting schedule. We design and
analyze an approximation algorithm that runs in time polynomial in n, m and k
and computes a solution with an approximation factor that can be made
arbitrarily close to 3/2.Comment: A conference version of this paper has been accepted for publication
in the proceedings of the 14th Algorithms and Data Structures Symposium
(WADS
Effective spatial dimension of extremal non-dilatonic black p-branes and the description of entropy on the world volume
By investigating the critical behavior appearing at the extremal limit of the
non-dilatonic, black p-branes in (d+p) dimensions, we find that some critical
exponents related to the critical point obey the scaling laws. From the scaling
laws we obtain that the effective spatial dimension of the non-dilatonic black
holes and black strings is one, and is p for the non-dilatonic black p-branes.
For the dilatonic black holes and black p-branes, the effective dimension will
depend on the parameters in theories. Thus, we give an interpretation why the
Bekenstein-Hawking entropy may be given a simple world volume interpretation
only for the non-dilatonic black p-branes.Comment: 4 pages, RevTex, no figures, to appear in Phys. Rev. Let
Branes, AdS gravitons and Virasoro symmetry
We consider travelling waves propagating on the anti-de Sitter (AdS)
background. It is pointed out that for any dimension d, this space of solutions
has a Virasoro symmetry with a non-zero central charge. This result is a
natural generalization to higher dimensions of the three-dimensional
Brown-Henneaux symmetry.Comment: 4 pages REVTe
Black Hole Hair Removal: Non-linear Analysis
BMPV black holes in flat transverse space and in Taub-NUT space have
identical near horizon geometries but different microscopic degeneracies. It
has been proposed that this difference can be accounted for by different
contribution to the degeneracies of these black holes from hair modes, --
degrees of freedom living outside the horizon. In this paper we explicitly
construct the hair modes of these two black holes as finite bosonic and
fermionic deformations of the black hole solution satisfying the full
non-linear equations of motion of supergravity and preserving the supersymmetry
of the original solutions. Special care is taken to ensure that these solutions
do not have any curvature singularity at the future horizon when viewed as the
full ten dimensional geometry. We show that after removing the contribution due
to the hair degrees of freedom from the microscopic partition function, the
partition functions of the two black holes agree.Comment: 40 pages, LaTe
Radiation from a class of string theoretic black holes
The emission of a scalar with low energy , from a
dimensional black hole with n charges is studied in both string and
semiclassical calculations. In the lowest order in , the weak coupling
string and semiclassical calculations agree provided that the
Bekenstein--Hawking formula is valid and the effective central charge
for any D. When the next order in is considered however,
there is no agreement between the two schemes unless D=5, n=3 or D=4, n=4.Comment: 20 pages, Late
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