16094871
Non-linear realization of PSU(2,2|4) on the light-cone
The symmetries of the N=4 SuperYang-Mills theory on the light-cone are discussed, solely in terms of its physical degrees of freedom. We derive explicit expressions for the generators of the PSU(2,2|4) superalgebra, both in the free theory, and to all orders in the gauge coupling of the classical theory. We use these symmetries to construct its Hamiltonian, and show that it can be written as a quadratic form of a fermionic superfield.
118247985
N=5 three-algebras and 5-graded Lie superalgebras
We discuss a generalization of N=6 three-algebras to N=5 three-algebras in connection to anti-Lie triple systems and basic Lie superalgebras of type II. We then show that the structure constants defined in anti-Lie triple systems agree with those of N=5 superconformal theories in three dimensions.
120898350
Surplus Solid Angle in Horava-Lifshitz Gravity
We consider Hořava-Lifshitz gravity coupled to the electrostatic field of a point charge, and show that the static solutions describe a space with a surplus (or deficit) solid angle. Unlike in general relativity, appearance of a surplus angle seems generic in Hořava-Lifshitz gravity. We discuss possible astrophysical effects due to a surplus angle.
18632800
Soliton and Domain Wall in the Self-Dual Ferromagnet
We perform the dimensional reduction of a uniaxial planar ferromagnet system coupled to an Abelian Chern-Simons gauge field in the self-dual limit, and investigate the soliton and domain wall solutions of the emerging 1+1 dimensional self-dual system. This self-dual ferromagnet is the usual inhomogeneous Landau-Lifshitz system with an extra non-local term supplementing the anisotropic potential energy. The Hamiltonian is Bogomol’nyi bounded from below and has four adjusting parameters. The Bogomol’nyi equation is described in detail in analogy with the Newtonian equation of motion and its numerical solution is presented. PACS codes: 11.10.Lm, 11.27.+d
119199828
The general M5-brane superconformal index
We calculate and study the general superconformal index for the 6d U(N) (2,0) theory with four chemical potentials, from the indices of gauge theories on CP^2 x R. Our index agrees with the large N supergravity index on AdS_7 x S^4 at low energies, and also yields the negative 'Casimir energy' with an N^3 scaling which was recently calculated from a QFT on S^5. Our approach also suggests a systematic study of the (1,0) superconformal indices.
44214844
Abelian decomposition of Einstein's theory: Reformulation of general relativity
We propose a reformulation of general relativity by making the Abelian decomposition of Einstein's theory. Based on the view that Einstein's theory can be interpreted as a gauge theory of Lorentz group, we decompose the Einstein's gravitational connection (the gauge potential of Lorentz group $\vGm_\mu$) into the restricted connection made of the potential of the maximal Abelian subgroup $H$ of Lorentz group $G$ and the valence connection made of $G/H$ part of the potential which transforms covariantly under Lorentz group. With this decomposition we show that the Einstein's theory can be decomposed into the restricted part made of the restricted connection which has the full Lorentz gauge invariance and the valence part made of the valence connection which plays the role of gravitational source of the restricted gravity. We show that there are two different Abelian decomposition of Einstein's theory, because Lorentz group has two maximal Abelian subgroups. In this decomposition the role of the space-time metric $g_\mn$ is replaced by a four-index metric tensor $\vg_\mn$ which transforms covariantly under the Lorentz group, and the metric-compatibility condition $\nabla_\alpha g_\mn=0$ of the connection is replaced by the gauge covariant condition $D_\mu \vg^\mn$ which tells that $\vg_\mn$ is invariant under the parallel transport along the $\pro_\mu$-direction defined by $\vGm_\mu$. We discuss the physical implications of the Abelian decomposition. In particular, we argue that the decomposition implies the existence of a restricted theory of gravitation which has the full general invariance but has less physical degrees of freedom.
118275742
Supersymmetry non-renormalization theorem from a computer and the AdS/CFT correspondence
We perform Monte Carlo calculation of correlation functions in 4d N=4 super Yang-Mills theory on R*S^3 in the planar limit. In order to circumvent the well-known problem of lattice SUSY, we adopt the idea of a novel large-N reduction, which reduces the calculation to that of corresponding correlation functions in the plane-wave matrix model or the BMN matrix model. This model is a 1d gauge theory with 16 supersymmetries, which can be simulated in a manner similar to the recent studies of the D0-brane system. We study two-point and three-point functions of chiral primary operators at various coupling constant, and find that they agree with the free theory results up to overall constant factors. The ratio of the overall factors for two-point and three-point functions agrees with the prediction of the AdS/CFT correspondence.
16066531
Dynamical Friction on Galactic Center Star Clusters with an Intermediate-Mass Black Hole
Numerical simulations of the dynamical friction suffered by a Galactic center star cluster harboring an intermediate-mass black hole (IMBH) have been performed. Gerhard has suggested that dynamical friction, which causes a cluster to lose orbital energy and spiral in toward the Galactic center, may explain the presence of a cluster of very young stars in the central parsec, where star formation might be prohibitively difficult because of strong tidal forces. However, numerical simulations by Kim & Morris showed that this is possible only if the cluster initially has an extremely dense core. Hansen & Milosavljevic recently suggested that the presence of an IMBH in the cluster core might stabilize the core against tidal disruption during the inspiral through dynamical friction and thus might easily deliver young stars down to the central parsec. We find that the presence of an IMBH does lower the minimum initial core density required to transport young stars down to the central parsec, but this is possible only when the mass of the IMBH is at least ~10% of the total cluster mass. This fraction is significantly higher than that estimated by Portegies Zwart & McMillan with numerical simulations of IMBH formation by successive merging of stars in the cluster core, so it does not appear that a realistic IMBH can help transport young stars into the central parsec.
119303854
Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube
Abstract We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 in. photomultiplier tube were measured with a 400 MHz FADC up to 16 μ s time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.
119276928
Measurement of central exclusive $\pi^+ \pi^-$ production in $p\bar{p}$ collisions at $\sqrt{s} = 0.9$ and 1.96 TeV at CDF
We measure exclusive π+π- production in proton-antiproton collisions at center-of-mass energies s=0.9 and 1.96 TeV in the Collider Detector at Fermilab. We select events with two oppositely charged particles, assumed to be pions, with pseudorapidity |η|<1.3 and with no other particles detected in |η|<5.9. We require the π+π- system to have rapidity |y|<1.0. The production mechanism of these events is expected to be dominated by double pomeron exchange, which constrains the quantum numbers of the central state. The data are potentially valuable for isoscalar meson spectroscopy and for understanding the pomeron in a region of transition between nonperturbative and perturbative quantum chromodynamics. The data extend up to dipion mass M(π+π-)=5000  MeV/c2 and show resonance structures attributed to f0 and f2(1270) mesons. From the π+π- and K+K- spectra, we place upper limits on exclusive χc0(3415) production.