11,308 research outputs found
Heavy Quarks in Strongly Coupled Non-Conformal Plasmas with Anisotropy
We analysis physical observables of heavy quarks in gravity models describing
strongly coupled non-conformal plasmas with anisotropy via the gauge/gravity
duality. The focus lies on the binding energy of static quark-antiquark -)pairs, the maximum distance (screening distance) of a bound -pair
and the drag force on uniformly moving quarks in the hot plasma. In order to
discover universal behavior in the observables, the computations are worked out
in a two parameter deformation of pure gravity in spacetime with a
black brane which is assumed to be dual to a respective two parameter
deformation of =\,4 supersymmetric Yang-Mills (SYM) theory at
temperature . The deformation is designed to break isotropy and conformal
symmetry and is a solution to equations of motion of a gravity action.Comment: 32 pages, 14 figures, v2: references adde
A comparison of manual and automatic moth sampling methods (Lepidoptera : Arctiidae, Geometridae) in a rain forest in Costa Rica
Sampling with UV fluorescent light tubes is a commonly used technique both in applied and basic insect studies. Our study compares the performance of two such methods: manual sampling (light towers) and automatic sampling (funnel light traps). The abundance, diversity, and body size of moths representing two species-rich families (Lepidoptera: Arctiidae, Geometridae) were analyzed in a lowland rain forest in Costa Rica (La Selva Biological Station, 10.4 degrees N, 84.0 degrees W) during 2003 and 2004. Light towers were equipped with two 15-W UV fluorescent tubes and were operated for 3 h in 16 nights. Traps equipped with single 8-W fluorescent tubes were run throughout 20 nights in the understory of the forest. In addition, parallel trap sampling was carried out in the canopy. A total of 1,238 arctiid moths representing 162 species and 1,769 geometrid moths representing 196 species were collected. In Geometridae, tower samples were significantly larger than trap samples. Towers also attracted a higher overall number of species. Very small geometrids (particularly of the subfamily Sterrhinae) were under-represented in trap samples, suggesting that this method is biased toward larger species. In arctiid moths, there were no significant differences in either the sample sizes, the number of species or in the size of the individuals sampled. Diversity calculated as Fisher's a was similar for towers and understory traps in both families. A major component of diversity was added with canopy trap samples for arctiid moths, but not for geometrid moths. In conclusion, ground-based tower sampling proved to be the most suitable method for geometrid moths, and trap sampling including both understory and canopy for arctiid moths. For full moth species inventories, a combination of both approaches is recommended
Entanglement entropy through conformal interfaces in the 2D Ising model
We consider the entanglement entropy for the 2D Ising model at the conformal
fixed point in the presence of interfaces. More precisely, we investigate the
situation where the two subsystems are separated by a defect line that
preserves conformal invariance. Using the replica trick, we compute the
entanglement entropy between the two subsystems. We observe that the entropy,
just like in the case without defects, shows a logarithmic scaling behavior
with respect to the size of the system. Here, the prefactor of the logarithm
depends on the strength of the defect encoded in the transmission coefficient.
We also comment on the supersymmetric case.Comment: 27 pages, 3 figures, v2: additional references and minor correction
The role of word frequency and morpho-orthography in agreement processing
Agreement attraction in comprehension (when an ungrammatical verb is read quickly if preceded by a feature-matching local noun) is well described by a cue-based retrieval framework. This suggests a role for lexical retrieval in attraction. To examine this, we manipulated two probabilistic factors known to affect lexical retrieval: local noun word frequency and morpho-orthography (agreement morphology realised with or without –s endings) in a self-paced reading study. Noun number and word frequency affected noun and verb region reading times, with higher-frequency words not eliciting attraction. Morpho-orthography impacted verb processing but not attraction: atypical plurals led to slower verb reading times regardless of verb number. Exploratory individual difference analyses further underscore the importance of lexical retrieval dynamics in sentence processing. This provides evidence that agreement operates via a cue-based retrieval mechanism over lexical representations that vary in their strength and association to number features
Probing thermality beyond the diagonal
We investigate the off-diagonal sector of eigenstate thermalization using
both local and non-local probes in 2-dimensional conformal field theories. A
novel analysis of the asymptotics of OPE coefficients via the modular bootstrap
is performed to extract the behaviour of the off-diagonal matrix elements. We
also probe this sector using semi-classical heavy-light Virasoro blocks. The
results demonstrate signatures of thermality and confirms the entropic
suppression of the off-diagonal elements as necessitated by the eigenstate
thermalization hypothesis.Comment: 27 pages, 2 figure
Multiple-View Tracing for Haskell: a New Hat
Different tracing systems for Haskell give different views of a program at work. In practice, several views are complementary and can productively be used together. Until now each system has generated its own trace, containing only the information needed for its particular view. Here we present the design of a trace that can serve several views. The trace is generated and written to file as the computation proceeds. We have implemented both the generation of the trace and several different viewers
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