349 research outputs found
The string spectrum on the horizon of a non-extremal black hole
We investigate the conformal string -model corresponding to a
general five-dimensional non-extremal black hole solution. In the horizon
region the theory reduces to an exactly solvable conformal field theory. We
determine the modular invariant spectrum of physical string states, which
expresses the Rindler momentum operator in terms of three charges and string
oscillators. For black holes with winding and Kaluza-Klein charges, we find
that states made with only right-moving excitations have ADM mass equal to the
black hole ADM mass, and thus they can be used as sources of the gravitational
field. A discussion on statistical entropy is included.Comment: 17 pages, harvmac (minor corrections
Gender Discrimination in Hiring: Evidence from a Cross-National Harmonized Field Experiment
© The Author(s) 2021. Published by Oxford University Press.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/),
which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly citedGender discrimination is often regarded as an important driver of womenâs disadvantage in the labour market, yet earlier studies show mixed results. However, because different studies employ different research designs, the estimates of discrimination cannot be compared across countries. By utilizing data from the first harmonized comparative field experiment on gender discrimination in hiring in six countries, we can directly compare employersâ callbacks to fictitious male and female applicants. The countries included vary in a number of key institutional, economic, and cultural dimensions, yet we found no sign of discrimination against women. This cross-national finding constitutes an important and robust piece of evidence. Second, we found discrimination against men in Germany, the Netherlands, Spain, and the UK, and no discrimination against men in Norway and the United States. However, in the pooled data the gender gradient hardly differs across countries. Our findings suggest that although employers operate in quite different institutional contexts, they regard female applicants as more suitable for jobs in female-dominated occupations, ceteris paribus, while we find no evidence that they regard male applicants as more suitable anywhere.This project received funding from the European Unionâs Horizon 2020 research and innovation program under grant agreement No 649255; the Research Council of Norway, grant number 287016; The Netherlands Organization for Scientific Research (NWO), (016.Vidi.185.041)Peer reviewe
PP-Wave / CFT_2 Duality
We investigate the pp-wave limit of the AdS_3\times S^3\times K3
compactification of Type IIB string theory from the point of view of the dual
Sym_N(K3) CFT. It is proposed that a fundamental string in this pp-wave
geometry is dual to the c=6 effective string of the Sym_N(K3) CFT, with the
string bits of the latter being composed of twist operators. The massive
fundamental string oscillators correspond to certain twisted Virasoro
generators in the effective string. It is shown that both the ground states and
the genus expansion parameter (at least in the orbifold limit of the CFT)
coincide. Surprisingly the latter scales like J^2/N rather than the J^4/N^2
which might have been expected. We demonstrate a leading-order agreement
between the pp-wave and CFT particle spectra. For a degenerate special case
(one NS 5-brane) an intriguing complete agreement is found.Comment: JHEP3 LaTeX, 20 pages; discussion of WZW levels clarified, reference
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Parallel Recursive State Compression for Free
This paper focuses on reducing memory usage in enumerative model checking,
while maintaining the multi-core scalability obtained in earlier work. We
present a tree-based multi-core compression method, which works by leveraging
sharing among sub-vectors of state vectors.
An algorithmic analysis of both worst-case and optimal compression ratios
shows the potential to compress even large states to a small constant on
average (8 bytes). Our experiments demonstrate that this holds up in practice:
the median compression ratio of 279 measured experiments is within 17% of the
optimum for tree compression, and five times better than the median compression
ratio of SPIN's COLLAPSE compression.
Our algorithms are implemented in the LTSmin tool, and our experiments show
that for model checking, multi-core tree compression pays its own way: it comes
virtually without overhead compared to the fastest hash table-based methods.Comment: 19 page
Open String Fluctuations in AdS with and without Torsion
The equations of motion and boundary conditions for the fluctuations around a
classical open string, in a curved space-time with torsion, are considered in
compact and world-sheet covariant form. The rigidly rotating open strings in
Anti de Sitter space with and without torsion are investigated in detail. By
carefully analyzing the tangential fluctuations at the boundary, we show
explicitly that the physical fluctuations (which at the boundary are
combinations of normal and tangential fluctuations) are finite, even though the
world-sheet is singular there. The divergent 2-curvature thus seems less
dangerous than expected, in these cases. The general formalism can be
straightforwardly used also to study the (bosonic part of the) fluctuations
around the closed strings, recently considered in connection with the AdS/CFT
duality, on AdS_5 \times S^5 and AdS_3 \times S^3 \times T^4.Comment: 19 pages, Late
Young star clusters in M31
In our study of M31's globular cluster system with MMT/Hectospec, we have
obtained high-quality spectra of 85 clusters with ages less than 1 Gyr. With
the exception of Hubble V, the young cluster in NGC 205, we find that these
young clusters have kinematics and spatial distribution consistent with
membership in M31's young disk. Preliminary estimates of the cluster masses and
structural parameters, using spectroscopically derived ages and HST imaging,
confirms earlier suggestions that M31 has clusters similar to the LMC's young
populous clusters.Comment: 4 pages, 1 figure, contributed talk at "Galaxies in the Local Volume"
conference in Sydney, July 200
Spinning Pulsating String Solitons in AdS_5 x S^5
We point out the existence of some simple string solitons in AdS_5 x S^5,
which at the same time are spinning in AdS_5 and pulsating in S^5, or
vice-versa. This introduces an additional arbitrary constant into the scaling
relations between energy and spin or R-charge. The arbitrary constant is not an
angular momentum, but can be related to the amplitude of the pulsation. We
discuss the solutions in detail and consider the scaling relations. Pulsating
multi spin or multi R-charge solutions can also be constructed.Comment: 15 pages, Late
Synthesis of deuteriumâlabelled amlexanox and its metabolic stability against mouse, rat, and human microsomes
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149374/1/jlcr3716_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149374/2/jlcr3716.pd
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