218 research outputs found
Thermodynamics of Intersecting Black Branes from Interacting Elementary Branes
If an Einstein-Maxwell-Dilaton system admits the extreme brane solution in
which no force works between the parallel branes, the collective motion of
nearly parallel branes exhibits the thermodynamical properties which are
coincident with those of the corresponding black branes at low energy regime
(up to unfixed numerical factors). Hence it may provide the microscopic
description of the black branes (-soup proposal). This fact motivates us to
test this proposal in the intersecting black branes which have multiple brane
charges and/or momentum along the brane direction. We consider the case that
the multiple branes satisfy the intersection rule and feel no force when they
are static, and find the agreement to the black hole thermodynamics.Comment: 1+17 page
Spatiotemporal heterogeneity of local free volumes in highly supercooled liquid
We discuss the spatiotemporal behavior of local density and its relation to
dynamical heterogeneity in a highly supercooled liquid by using molecular
dynamics simulations of a binary mixture with different particle sizes in two
dimensions. To trace voids heterogeneously existing with lower local densities,
which move along with the structural relaxation, we employ the minimum local
density for each particle in a time window whose width is set along with the
structural relaxation time. Particles subject to free volumes correspond well
to the configuration rearranging region of dynamical heterogeneity. While the
correlation length for dynamical heterogeneity grows with temperature decrease,
no growth in the correlation length of heterogeneity in the minimum local
density distribution takes place. A comparison of these results with those of
normal mode analysis reveals that superpositions of lower-frequency soft modes
extending over the free volumes exhibit spatial correlation with the broken
bonds. This observation suggests a possibility that long-ranged vibration modes
facilitate the interactions between fragile regions represented by free
volumes, to induce dynamical correlations at a large scale.Comment: 9 pages, 9 figures, typos are correcte
Microstates of D1-D5(-P) black holes as interacting D-branes
In our previous study [1] (1311.6540), we figured out that the thermodynamics
of the near extremal black -branes can be explained as the collective
motions of gravitationally interacting elementary -branes (the -soup
proposal). We test this proposal in the near-extremal D1-D5 and D1-D5-P black
holes and show that their thermodynamics also can be explained in a similar
fashion, i.e. via the collective motions of the interacting elementary
D1-branes and D5-branes (and waves). It may imply that the microscopic origins
of these intersecting black branes and the black -brane are explained in the
unified picture. We also argue the relation between the -soup proposal and
the conformal field theory calculations of the D1-D5(-P) black holes in
superstring theory.Comment: 1+11 pages, no figures; v2: minor correction
Warm p-soup and near extremal black holes
We consider a model of D-dimensional supergravity coupled to elementary
p-branes. We use gravitational arguments to deduce the low energy effective
theory of N nearly parallel branes. This is a (p+1)-dimensional scalar field
theory, where the scalars represent the positions of the branes in their
transverse space. We propose that the same theory in a certain temperature
regime describes a `soup' of strongly interacting branes, giving a microscopic
description of near extremal black p-branes. We use natural approximations to
estimate the energy density of this soup as a function of the physical
parameters; N, temperature, brane tension and gravitational coupling. We also
characterise the horizon radius, measured in the metric natural to the branes,
with the thermal vev of the scalars. For both quantities we find agreement with
the corresponding supergravity black brane results. Surprisingly, beyond the
physical parameters, we are naturally able to reproduce certain irrational
factors such as pi's. We comment on how these ideas may explain why black hole
thermodynamics arises in gauge theories with holographic duals at finite
temperature.Comment: 32 pages, no figure
The MOOC Syllabus Blues: Strategies for MOOCs and Syllabus Materials
Maximally supersymmetric (p+1)-dimensional Yang-Mills theory at large N and finite temperature, with possibly compact spatial directions, has a rich phase structure. Strongly coupled phases may have holographic descriptions as black branes in various string duality frames, or there may be no gravity dual. In this paper we provide tools in the gauge theory which give a simple and unified picture of the various strongly coupled phases, and transitions between them. Building on our previous work we consider the effective theory describing the moduli of the gauge theory, which can be computed precisely when it is weakly coupled far out on the Coulomb branch. Whilst for perturbation theory naive extrapolation from weak coupling to strong gives little information, for this moduli theory naive extrapolation from its weakly to its strongly coupled regime appears to encode a surprising amount of information about the various strongly coupled phases. We argue it encodes not only the parametric form of thermodynamic quantities for these strongly coupled phases, but also certain transcendental factors with a geometric origin, and allows one to deduce transitions between the phases. We emphasise it also gives predictions for the behaviour of a large class of local operators in these phases
Groove Pancreatitis with Several Cystic Lesions around the Pancreatic Head Treated Conservatively: Report of a Case
A 61-year-old man was admitted to our hospital with epigastric pain and vomiting. Enhanced abdominal computed tomography revealed inflammatory change of the pancreatic groove and focal wall thickening of the second portion of the duodenum with several cystic lesions around the head of the pancreas. We diagnosed atypical type of groove pancreatitis. The patient made a satisfactory recovery by conservative medication treatment for acute on chronic pancreatitis and cystic lesions disappeared in parallel with pancreatitis. Groove pancreatitis is a rare form of chronic pancreatitis, and to the best of our knowledge, our patient is the first case in the English literature of groove pancreatitis with cystic lesions around the head of the pancreas, which disappeared after conservative treatment for pancreatitis
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