47 research outputs found
Probing Smearing Effect by Point-Like Graviton in Plane-Wave Matrix Model
We investigate the interaction between flat membrane and point-like graviton
in the plane-wave matrix model. The one-loop effective potential in the large
distance limit is computed and is shown to be of r^{-3} type where r is the
distance between two objects. This type of interaction has been interpreted as
the one incorporating the smearing effect due to the configuration of flat
membrane in plane-wave background. Our result supports this interpretation and
provides one more evidence about it.Comment: 22 pages, LaTeX2
Conductivity in the anisotropic background
By using the gauge/gravity duality, we investigate the dual field theories of
the anisotropic backgrounds, which are exact solutions of
Einstein-Maxwell-dilaton theory with a Liouville potential. When we turn on the
bulk gauge field fluctuation with a non-trivial dilaton coupling, the AC
conductivity of this dual field theory is proportional to the frequency with an
exponent depending on parameters of the anisotropic background. In some
parameter regions, we find that this conductivity can have the negative
exponent like the strange metal. In addition, we also investigate another U(1)
gauge field fluctuation, which is not coupled with a dilaton field. We classify
all possible conductivities of this system and find that the exponent of the
conductivity is always positive.Comment: 22 pages, 13 figures, added some comments and reference
Domain wall cosmology and multiple accelerations
We classify the cosmological behaviors of the domain wall under junctions
between two spacetimes in terms of various parameters: cosmological constants
of bulk spacetime, a tension of a domain wall, and mass parameters of the black
hole-type metric. Especially, we consider the false-true vacuum type junctions
and the domain wall connecting between an inner AdS space and an outer AdS
Reissner-Nordstrm black hole. We find that there exist a
solution to the junction equations with an inflation at earlier times and an
accelerating expansion at later times.Comment: corrected typos, title and sec.
Properties of Holographic Mesons on Dense Medium
We study the energy dispersions of holographic light mesons and their decay
constants on dense nuclear medium. As the spatial momenta of mesons along the
boundary direction increase, both observables of the mesons not only increase
but also split according to the isospin charges. The decay constant of the
negative meson is more large than that of the positive meson of the same type
due to the chemical potentials of the background nucleons.Comment: 18 pages, 8 Fig. number
Dynamics of false vacuum bubbles with nonminimal coupling
We study the dynamics of false vacuum bubbles. A nonminimally coupled scalar
field gives rise to the effect of negative tension. The mass of a false vacuum
bubble from outside observer's point of view can be positive, zero, or
negative. The interior false vacuum has de Sitter geometry, while the exterior
true vacuum background can have geometry depending on the vacuum energy. We
show that there exist expanding false vacuum bubbles without the initial
singularity in the past.Comment: 17 pages, 13 figure
5,5′-[1,4-Phenylenebis(methylenesulfanediyl)]bis[1,3,4-thiadiazol-2(3H)-one] dimethyl sulfoxide disolvate
The asymmetric unit of the title compound, C12H10N4O2S4·2C2H6OS, contains one half of the p-xylene molecule and one dimethyl sulfoxide molecule. The p-xylene molecule is located about a crystallographic inversion centre. In the molecule, the thiadiazole and benzene rings are almost perpendicular to one another, with a dihedral angle of 88.95 (6)°. In the crystal, an N—H⋯O hydrogen bond is observed between the two components. The dimethyl sulfoxide molecule is disordered over two orientations with an occupancy ratio of 0.879 (1):0.121 (1)
N-(5-Sulfanylidene-4,5-dihydro-1,3,4-thiadiazol-2-yl)acetamide dimethyl sulfoxide disolvate
In the title compound, C4H5N3OS2·2C2H6OS, the five-membered heterocyclic ring and the N—(C=O)—C plane of the acetamide group are essentially co-planar, with a dihedral angle of 1.25 (3)°. Intermolecular N—H⋯O hydrogen bonds between the acetamide compound and the dimethyl sulfoxide molecules stabilize the crystal structure. The two dimethyl sulfoxide molecules are each disordered over two positions with occupancy ratios of 0.605 (2):0.395 (2) and 0.8629 (18):0.1371 (18)
5-Amino-1,3,4-thiadiazol-2(3H)-one
The asymmetric unit of the title compound, C2H3N3OS, contains three independent molecules which are essentially planar, with r.m.s. deviations of 0.011 (2)–0.027 (2) Å from the mean plane defined by the seven non-H atoms. In the crystal, N—H⋯N and N—H⋯O hydrogen bonds link the molecules into a sheet parallel to the (111) plane