2,164 research outputs found
A quantum-mechanical study of optical regenerators based on nonlinear-loop mirrors
We present a quantum-mechanical analysis of a nonlinear interferometer that
achieves optical switching via cross-phase modulation resulting from the Kerr
effect. We show how it performs as a very precise optical regenerator, highly
improving the transmitted bit-error rate in the presence of loss.Comment: 420KB tar file, including 5 eps figures. To appear on IEEE Photonics
Technology Letter
Gravitino Zero Modes on U(1)_R Strings
We consider theories with a spontaneously broken gauged R-symmetry, which can
only occur in supergravity models. These give rise to cosmic R-strings upon
which gravitino zero modes can exist. We construct solutions to the
Rarita-Schwinger spin-3/2 equation describing the gravitino in the field of
these cosmic strings and show that under some conditions these solutions may
give rise to gravitino currents on the string. We discuss further mathematical
and physical questions associated with these solutions.Comment: 18 pages, uses revte
Higher rank Wilson loops from a matrix model
We compute the circular Wilson loop of N=4 SYM theory at large N in the rank
k symmetric and antisymmetric tensor representations. Using a quadratic
Hermitian matrix model we obtain expressions for all values of the 't Hooft
coupling. At large and small couplings we give explicit formulae and reproduce
supergravity results from both D3 and D5 branes within a systematic framework.Comment: 1+18 pages. 1 figure. Typos correcte
Supersymmetric Lifshitz-like backgrounds from = 4 SYM with heavy quark density
We examine a class of gravity backgrounds obtained by considering the backreaction of a spatially uniform density of mutually BPS Wilson lines or heavy quarks in N = 4 SUSY Yang-Mills theory. The configurations preserve eight supercharges and an SO(5) subgroup of the SO(6) R-symmetry. They are obtained by considering the 1 -BPS geometries associated to smeared string/D3-brane (F1-D3) intersections. We argue that for the (partially) localized intersection, the geometry exhibits a flow from AdS5 × S5 in the UV to a novel IR scaling solution displaying anisotropic Lifshitz-like scaling with dynamical critical exponent z = 7, hyperscaling violation and a logarithmic running dilaton. We also obtain a two-parameter family of smeared 1-BPS solutions on the Coulomb branch of N = 4 SYM exhibiting Lifshitz scaling and hyperscaling violation. For a certain parametric range these yield IR geometries which are conformal to AdS2 × R3, and which have been argued to be relevant for fermionic physics
Higher spin entanglement entropy from CFT
We consider free fermion and free boson CFTs in two dimensions, de- formed by a chemical potential μ for the spin-three current. For the CFT on the infinite spatial line, we calculate the finite temperature entanglement entropy of a single interval perturbatively to second order in μ in each of the theories. We find that the result in each case is given by the same non-trivial function of temperature and interval length. Remarkably, we further obtain the same formula using a recent Wilson line proposal for the holographic entanglement entropy, in holomorphically factorized form, associated to the spin-three black hole in SL(3, R) × SL(3, R) Chern- Simons theory. Our result suggests that the order μ2 correction to the entanglement entropy may be universal for W-algebra CFTs with spin-three chemical potential, and constitutes a check of the holographic entanglement entropy proposal for higher spin theories of gravity in AdS3
Universal correction to higher spin entanglement entropy
We consider conformal field theories in two spacetime dimensions with W-algebra symmetries, deformed by a chemical potential μ for the spin-three current. We show that the order μ2 correction to the R ́enyi and entanglement entropies of a single interval in the deformed theory, on the infinite spatial line and at finite temperature, is universal. The correction is completely determined by the operator product expansion of two spin-three currents, and by the expectation values of the stress tensor, its descendants and its composites, evaluated on the n-sheeted Riemann surface branched along the interval. This explains the recently found agreement of the order μ2 correction across distinct free field CFTs and higher spin black hole solutions holographically dual to CFTs with W-symmetry
Migration and Women Empowerment in India: An Overview of Pattern of Female Migration, its Causes and Consequences
Trend and pattern of migration reveals socio-economic condition of the population In India pattern and level of internal migration among males and females are quite different The reasons of migration among females are entirely different from those of males Gender gap in employment and empowerment is manifested by the strikingly different pattern of migration among female and male populatio
A rare case of myofibroblastoma in the nipple of a male patient and review of literature.
           Myofibroblastoma of breast is described both in male and female breast but myofibroblastoma of the nipple is so far not reported. We are reporting a case of myofibroblastoma of nipple in a male which was treated by wide excision of nipple. Myofibroblastoma of the breast is an uncommon benign stromal tumor encountered predominantly in men in their sixth to seventh decades and in post-menopausal women.Myofibroblasts are spindleshaped or fusiform mesenchymal cells derived from fibroblasts and are present in small numbers in all tissues.Mammographic findings consist of a well-delimited, round to oval dense mass, variable in size but usually 1-4 cm in diameter. Although FNA cytology may support the diagnosis, surgical biopsy should be performed.  A simple surgical excision is required for this benign lesion. No recurrence has been observed.Â
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