Concurrence is an entanglement measure characterizing the mixed state bipartite correlations inside of a pure state of an $n$-qubit system. We show that after organizing the charges and the moduli in the STU model of $N=2$, $d=4$ supergravity to a three-qubit state, for static extremal spherically symmetric Bogomolny-Prasad-Sommerfield (BPS) black-hole solutions the vanishing condition for all of the bipartite concurrences on the horizon is equivalent to the attractor equations. As a result of this, the macroscopic black hole entropy given by the three-tangle can be reinterpreted as a linear entropy characterizing the pure state entanglement for an arbitrary bipartite split. Both for the BPS and non-BPS cases, explicit expressions for the concurrences are obtained, with their vanishing on the horizon is demonstrated.

We consider the region $\mathcal{T}$ in spacetime containing future-trapped closed surfaces and its boundary $\mathcal{B}$, and derive some of their general properties. We then concentrate on the case of spherical symmetry, but the methods we use are general and applicable to other situations. We argue that closed trapped surfaces have a nonlocal property, “clairvoyance”, which is inherited by $\mathcal{B}$. We prove that $\mathcal{B}$ is not a marginally trapped tube in general, and that it can have portions in regions whose whole past is flat. For asymptotically flat black holes, we identify a general past barrier, well inside the event horizon, to the location of $\mathcal{B}$ under physically reasonable conditions. We also define the core $\mathcal{Z}$ of the trapped region as that part of $\mathcal{T}$ which is indispensable to sustain closed trapped surfaces. We prove that the unique spherically symmetric dynamical horizon is the boundary of such a core, and we argue that this may serve to single it out. To illustrate the results, some explicit examples are discussed, namely, Robertson-Walker geometries and the imploding Vaidya spacetime.

The primary target for the planned space-borne gravitational wave interferometers DECIGO/BBO (Decihertz Interferometer Gravitational Wave Observatory/Big Bang Observer) is a primordial gravitational wave background. However there exist astrophysical foregrounds, and among them, gravitational waves from neutron-star (NS) binaries are the solid and strong component that must be identified and subtracted. In this paper, we discuss the geometry of detector configurations preferable for identifying the NS/NS binary signals. As a first step, we analytically estimate the minimum signal-to-noise ratios of the binaries for several static detector configurations that are characterized by adjustable geometrical parameters, and determine the optimal values for these parameters. Next we perform numerical simulations to take into account the effect of detector motions, and find reasonable agreements with the analytical results. We show that, with the standard network formed by 4 units of triangle detectors, the proposed BBO sensitivity would be sufficient in receiving gravitational waves from all the NS/NS binaries at $z\le 5$ with signal-to-noise ratios higher than 25. We also discuss the minimum sensitivity of DECIGO required for the foreground identification.

We clarify the behavior of curvature perturbations in a nonlinear theory in case the inflaton temporarily stops during inflation. We focus on the evolution of curvature perturbation on superhorizon scales by adopting the spatial gradient expansion and show the nonlinear theory, called the beyond $\delta N$ formalism, for a general single scalar field as the next-leading order in the expansion. Both the leading order in the expansion ($\delta N$ formalism) and our nonlinear theory include the solutions of full-nonlinear orders in the standard perturbative expansion. Additionally, in our formalism, we can deal with the time evolution in contrast to $\delta N$ formalism, where curvature perturbations remain just constant, and show decaying modes do not couple with growing modes as similar to the case with the linear theory. We can conclude that, although the decaying mode diverges when $\dot{\varphi }$ vanishes, there appears no trouble for both the linear and nonlinear theory since these modes will vanish at late times.

The possible origin of the $R$-parity–violating interactions in the minimal supersymmetric standard model and its connection to the radiative symmetry-breaking mechanism is investigated in the context of the simplest model where the radiative symmetry-breaking mechanism can be implemented. We find that, in the majority of the parameter space, $R$ parity is spontaneously broken at the low scale. These results hint that $R$-parity–violating processes could be observed at the Large Hadron Collider, if supersymmetry is realized in nature.

We analyze the prospect for observing the intermediate neutral Higgs boson ($h_2$) in its decay to two lighter Higgs bosons ($h_1$) at the presently operating hadron colliders in the framework of the $CP$-violating minimal supersymmetric standard model using the PYTHIA event generator. We consider the $\mathrm{\text{lepton}}+4\mathrm{\text{−}}\mathrm{\text{jets}}+{\cancel{E}}_T$ channel from associate $W{h}_2$ production, with $W{h}_2\to W{h}_1{h}_1\to l{\nu }_{l}b\overline{b}b\overline{b}$. We require two, three or four tagged $b$ jets. We explicitly consider all relevant standard model backgrounds, treating $c$ jets separately from light flavor and gluon jets and allowing for mistagging. We find that it is very hard to observe this signature at the Tevatron, even with $20{\mathrm{fb}}^{-1}$ of data, in the LEP-allowed region of parameter space due to the small signal efficiency, even though the background is manageable. At the LHC, a priori huge standard model backgrounds can be suppressed by applying judiciously chosen kinematical selections. After all cuts, we are left with a signal cross section of around 0.5 fb, and a signal to background ratio between 1.2 and 2.9. According to our analysis this Higgs signal should be viable at the LHC in the vicinity of present LEP exclusion once 20 to $50{\mathrm{fb}}^{-1}$ of data have been accumulated at $\sqrt{s}=14\mathrm{TeV}$.

We have systematically calculated the S-wave pseudoscalar meson and decuplet baryon scattering lengths to the third order in the small-scale expansion scheme of the heavy baryon chiral perturbation theory. We hope that future study may test the framework and the present predictions.

Using $535\times {10}^6$ $B$-meson pairs collected by the Belle detector at the KEKB $e^{+}{e}^{-}$ collider, we measure branching fractions of $(7.16\pm 0.10(\mathrm{stat})\pm 0.60(\mathrm{syst})\times {10}^{-4}$ for $B^{+}\to J/\psi K^{+}{\pi }^{+}{\pi }^{-}$ and $(4.31\pm 0.20(\mathrm{stat})\pm 0.50(\mathrm{syst}))\times {10}^{-4}$ for $B^{+}\to {\psi }^{\prime }{K}^{+}{\pi }^{+}{\pi }^{-}$. We perform amplitude analyses to determine the resonant structure of the $K^{+}{\pi }^{+}{\pi }^{-}$ final state in $B^{+}\to J/\psi K^{+}{\pi }^{+}{\pi }^{-}$ and $B^{+}\to {\psi }^{\prime }{K}^{+}{\pi }^{+}{\pi }^{-}$ and find that the $K_1(1270)$ is a prominent component of both decay modes. There is significant interference among the different intermediate states, which leads, in particular, to a striking distortion of the $\rho$ line shape due to the $\omega$. Based on the results of the fit to the $B^{+}\to J/\psi K^{+}{\pi }^{+}{\pi }^{-}$ data, the relative decay fractions of the $K_1(1270)$ to $K\rho$, $K\omega$, and $K^{*}(892)\pi$ are consistent with previous measurements, but the decay fraction to $K_0^{*}(1430)$ is significantly smaller. Finally, by floating the mass and width of the $K_1(1270)$ in an additional fit of the $B^{+}\to J/\psi K^{+}{\pi }^{+}{\pi }^{-}$ data, we measure a mass of $(1248.1\pm 3.3(\mathrm{stat})\pm 1.4(\mathrm{syst}))\mathrm{MeV}/c^2$ and a width of $(119.5\pm 5.2(\mathrm{stat})\pm 6.7(\mathrm{syst}))\mathrm{MeV}/c^2$ for the $K_1(1270)$.

We present a measurement of the branching fractions of the 22 decay channels of the $B^0$ and $B^{+}$ mesons to ${\overline{D}}^{(*)}{D}^{(*)}K$, where the $D^{(*)}$ and ${\overline{D}}^{(*)}$ mesons are fully reconstructed. Summing the 10 neutral modes and the 12 charged modes, the branching fractions are found to be $\mathcal{B}(B^0\to {\overline{D}}^{(*)}{D}^{(*)}K)=(3.68\pm 0.10\pm 0.24)\%$ and $\mathcal{B}(B^{+}\to {\overline{D}}^{(*)}{D}^{(*)}K)=(4.05\pm 0.11\pm 0.28)\%$, where the first uncertainties are statistical and the second systematic. The results are based on $429{\mathrm{fb}}^{-1}$ of data containing $471\times {10}^{6}B\overline{B}$ pairs collected at the ${\rm Y}(4S)$ resonance with the BABAR detector at the SLAC National Accelerator Laboratory.

Using samples of $2.25\times {10}^8$ $J/\psi$ events and $1.06\times {10}^8$ ${\psi }^{\prime }$ events collected with the BES III detector, we study the $f_0(980)\to a_0^0(980)$ and $a_0^0(980)\to f_0(980)$ transitions in the processes $J/\psi \to \varphi f_0(980)\to \varphi a_0^0(980)$ and ${\chi }_{c1}\to {\pi }^0{a}_0^0(980)\to {\pi }^0{f}_0(980)$, respectively. Evidence for $f_0(980)\to a_0^0(980)$ is found with a significance of $3.4\sigma$, while in the case of $a_0^0(980)\to f_0(980)$ transition, the significance is $1.9\sigma$. Measurements and upper limits of both branching ratios and mixing intensities are determined.

We present a search for a new heavy charged vector boson $W^{\prime }$ decaying to an electron-neutrino pair in $p\overline{p}$ collisions at a center-of-mass energy of 1.96 TeV. The data were collected with the CDF II detector and correspond to an integrated luminosity of $5.3{\mathrm{fb}}^{-1}$. No significant excess above the standard model expectation is observed and we set upper limits on $\sigma ·\mathcal{B}(W^{\prime }\to e\nu )$. Assuming standard model couplings to fermions and the neutrino from the $W^{\prime }$ boson decay to be light, we exclude a $W^{\prime }$ boson with mass less than $1.12\mathrm{TeV}/c^2$ at the 95% confidence level.

We study bound orbits of a free particle around a singly rotating black ring. We find there exists chaotic motion of a particle which is gravitationally bound to the black ring by using the Poincaré map.

We refer to the ground state of a gravitating, charged ideal fluid of fermions held at a finite chemical potential as an “electron star.” In a holographic setting, electron stars are candidate gravity duals for strongly interacting finite fermion density systems. We show how electron stars develop an emergent Lifshitz scaling at low energies. This IR scaling region is a consequence of the two-way interaction between emergent quantum critical bosonic modes and the finite density of fermions. By integrating from the IR region to an asymptotically $Ad{S}_4$ spacetime, we compute basic properties of the electron stars, including their electrical conductivity. We emphasize the challenge of connecting UV and IR physics in strongly interacting finite density systems.

We discuss some new simple closed bosonic string solutions in ${\mathrm{AdS}}_5\times {\mathrm{S}}^5$ that may be of interest in the context of AdS/CFT duality. In the first part of this work we consider solutions with two spins $(S_1,S_2)$ in ${\mathrm{AdS}}_5$. Starting from the flat-space solutions and using perturbation theory in the curvature of ${\mathrm{AdS}}_5$ space, we construct leading terms in the small two-spin solution. We find corrections to the leading Regge term in the classical string energy and uncover a discontinuity in the spectrum for a certain type of solution. We then analyze the connection between small-spin and large-spin limits of string solutions in ${\mathrm{AdS}}_5$. We show that the $S_1=S_2$ solution in ${\mathrm{AdS}}_5$ found in earlier papers admits both limits only in the simplest cases of the folded and rigid circular strings. In the second part of the paper, we construct a new class of chiral solutions in $R_t\times S^5$ for which embedding coordinates of $S^5$ satisfy the linear Laplace equations. They generalize the previously studied rigid string solutions. We study in detail a simple nontrivial example.

Localization methods reduce the path integrals in $\mathcal{N}\ge 2$ supersymmetric Chern-Simons gauge theories on $S^3$ to multimatrix integrals. A recent evaluation of such a two-matrix integral for the $\mathcal{N}=6$ superconformal $U(N)\times U(N)$ Aharony-Bergman-Jafferis-Maldacena theory produced detailed agreement with the AdS/CFT correspondence, explaining, in particular, the $N^{3/2}$ scaling of the free energy. We study a class of $p$-matrix integrals describing $\mathcal{N}=3$ superconformal $U(N{)}^p$ Chern-Simons gauge theories. We present a simple method that allows us to evaluate the eigenvalue densities and the free energies in the large $N$ limit keeping the Chern-Simons levels $k_i$ fixed. The dual M-theory backgrounds are ${\mathrm{AdS}}_4\times Y$, where $Y$ are seven-dimensional tri-Sasaki Einstein spaces specified by the $k_i$. The gravitational free energy scales inversely with the square root of the volume of $Y$. We find a general formula for the $p$-matrix free energies that agrees with the available results for volumes of the tri-Sasaki Einstein spaces $Y$, thus providing a thorough test of the corresponding ${\mathrm{AdS}}_4/{\mathrm{CFT}}_3$ dualities. This formula is consistent with the Seiberg duality conjectured for Chern-Simons gauge theories.

We develop a diagrammatic representation of the Casimir energy of a multibody configuration. The diagrams represent multiple reflections between the objects and can be organized by a few simple rules. The lowest-order diagrams (or reflections) give the main contribution to the Casimir interaction which proves the usefulness of this expansion. Among some applications of this, we find analytical formulae describing the interaction between edges, i.e. semi-infinite plates, where we also give a first example of blocking in the context of the Casimir energy. We also find the interaction of edges with a needle and describe analytically a recent model of the repulsion due to the Casimir interaction.

We study the structure of the gauge sector of the Bagger-Lambert-Gustavsson theory in the form proposed by van Raamsdonk, adapted to three dimensions, $N=1$ superspace. By using the novel Higgs mechanism proposed by Mukhi and Papageorgakis, we derive the manifestly $N=1$ supersymmetric higher-order terms (beyond the supersymmetric Yang-Mills action) that follow from the Bagger-Lambert-Gustavsson theory in its expansion with respect to the inverse gauge coupling constant squared. We find that all those terms have at least one anticommutator of the super–Yang-Mills field strength superfields as a factor, and thus are reducible to the supersymmetric Yang-Mills terms with the higher (spacetime) derivatives.

In a recent paper published in this journal, Almeida and collaborators [Phys. Rev. D 79, 125022 (2009)] analyze the issue of fermion localization of fermions on a brane constructed from two scalar fields coupled with gravity (Bloch brane model). In that meritorious research the simplest Yukawa coupling $\eta \overline{\Psi }\varphi \chi \Psi$ was considered. That work does not analyze the zero mode in details. In this paper, the localization of fermions on two-field thick branes is reinvestigated. It is found that the simplest Yukawa coupling does not support the localization of fermions on the brane. In addition, the problem of fermion localization for some other Yukawa couplings are analyzed. It is shown that the zero mode for left-handed and right-handed fermions can be localized on the brane depending on the values for the coupling constant $\eta$ and the Bloch brane’s parameter $a$.

In this work, one shows that a generalized nonminimal coupling between geometry and matter is compatible with Starobinsky inflation and leads to a successful process of preheating, a reheating scenario based on the production of massive particles via parametric resonance. The model naturally extends the usual preheating mechanism, which resorts to an ad hoc scalar curvature-dependent mass term for a scalar field $\chi$, and also encompasses a previously studied preheating channel based upon a nonstandard kinetic term.

We present the full set of analytical solutions of the geodesic equations of charged test particles in the Reissner-Nordström space-time in terms of the Weierstraß $\wp$, $\sigma$, and $\zeta$ elliptic functions. Based on the study of the polynomials in the $\vartheta$ and $r$ equations, we characterize the motion of test particles and discuss their properties. The motion of charged test particles in the Reissner-Nordström space-time is compared with the motion of neutral test particles in the field of a gravitomagnetic monopole. Electrically or magnetically charged particles in the Reissner-Nordström space-time with magnetic or electric charges, respectively, move on cones similar to neutral test particles in the Taub-NUT space-times.