The coalescences of binary black hole systems, here taken to be nonspinning, are among the most promising sources for gravitational wave (GW) ground-based detectors, such as LIGO and Virgo. To detect the GW signals emitted by binary black holes and measure the parameters of the source, one needs to have in hand a bank of GW templates that are both effectual (for detection) and accurate (for measurement). We study the effectualness and the accuracy of the two types of parametrized banks of templates that are directly defined in the frequency domain by means of closed-form expressions, namely, “post-Newtonian” (PN) and “phenomenological” models. In the absence of knowledge of the (continuous family of) exact waveforms, our study assumes as fiducial, target waveforms the ones generated by the most accurate version of the effective-one-body formalism, calibrated upon a few high-accuracy numerical-relativity (NR) waveforms. We find that, for initial GW detectors the use, at each point of parameter space, of the best closed-form template (among PN and phenomenological models) leads to an effectualness $>97\%$ over the entire mass range and $>99\%$ in an important fraction of parameter space; however, when considering advanced detectors, both of the closed-form frequency-domain models fail to be effectual enough in significant domains of the two-dimensional [total mass and mass ratio] parameter space. Moreover, we find that, for both initial and advanced detectors, the two closed-form frequency-domain models fail to satisfy the minimal required accuracy standard in a very large domain of the two-dimensional parameter space. In addition, a side result of our study is the determination, as a function of the mass ratio, of the maximum frequency at which a frequency-domain PN waveform can be “joined” onto a NR-calibrated effective-one-body waveform without undue loss of accuracy. In the case of mass ratios larger than $4:1$ this maximum frequency occurs well before the last stable orbit, leaving probably too many orbital cycles to be covered by current NR techniques if one wanted to construct accurate-enough hybrid PN-NR waveforms. This problem will, however, be probably greatly alleviated, or even solved, by using the effective-one-body formalism instead of PN theory.

The search for solar axions produced by Compton ($\gamma +e^{-}\to e^{-}+A$) and bremsstrahlunglike ($e^{-}+Z\to Z+e^{-}+A$) processes has been performed. The axion flux in both cases depends on the axion-electron coupling constant. The resonant excitation of the low-lying nuclear level of ${}^{169}\mathrm{Tm}$ was looked for: $A+{}^{169}\mathrm{Tm}\to {}^{169}\mathrm{Tm}^{*}\to {}^{169}\mathrm{Tm}+\gamma$ (8.41 keV). The Si(Li) detector and ${}^{169}\mathrm{Tm}$ target installed inside the low-background setup were used to detect 8.41 keV $\gamma$ rays. As a result, a new model-independent restriction on the axion-electron and the axion-nucleon couplings was obtained: $g_{Ae}\times |g_{AN}^0+g_{AN}^3|\le 2.1\times {10}^{-14}$. In the model of the hadronic axion this restriction corresponds to the upper limit on the axion-electron coupling and on the axion mass $g_{Ae}\times m_A\le 3.1\times {10}^{-7}\mathrm{eV}$ (90% C.L.). The limits on the axion mass are $m_A\le 105\mathrm{eV}$ and $m_A\le 1.3\mathrm{keV}$ for the Dine-Fischler-Srednicki-Zhitnitskii- and Kim-Shifman-Vainstein-Zakharov-axion models, correspondingly (90% C.L.).

We suggest that white dwarf (WD) pulsars can compete with neutron star (NS) pulsars for producing the excesses of cosmic ray electrons and positrons ($e^{\pm }$) observed by the PAMELA, ATIC/PPB-BETS, Fermi, and H.E.S.S. experiments. A merger of two WDs leads to a rapidly spinning WD with a rotational energy ($\sim {10}^{50}\mathrm{erg}$) comparable to the NS case. The birth rate ($\sim {10}^{-2}–{10}^{-3}/\mathrm{yr}/\mathrm{\text{galaxy}}$) is also similar, providing the right energy budget for the cosmic ray $e^{\pm }$. Applying the NS theory, we suggest that the WD pulsars can in principle produce $e^{\pm }$ up to $\sim 10\mathrm{TeV}$. In contrast to the NS model, the adiabatic and radiative energy losses of $e^{\pm }$ are negligible since their injection continues after the expansion of the pulsar wind nebula, and hence it is enough that a fraction $\sim 1\%$ of WDs are magnetized ($\sim {10}^7–{10}^9\mathrm{G}$) as observed. The long activity also increases the number of nearby sources ($\sim 100$), which reduces the Poisson fluctuation in the flux. The WD pulsars could dominate the quickly cooling $e^{\pm }$ above TeV energy as a second spectral bump or even surpass the NS pulsars in the observing energy range $\sim 10\mathrm{GeV}–1\mathrm{TeV}$, providing a background for the dark matter signals and a nice target for the future AMS-02, CALET, and CTA experiment.

We calculate the next-to-leading order QCD corrections to the $J/\psi +W$ production at the LHC, and provide the theoretical distribution of the $J/\psi$ transverse momentum. Our results show that the differential cross section $\frac{d\sigma }{d{p}_T^{J/\psi }}$ at the leading order is significantly enhanced by the next-to-leading order QCD corrections. We believe that the comparison between the theoretical predictions for the $J/\psi +W$ production and the experimental data at the LHC can provide a verification for the color-octet mechanism of nonrelativistic QCD in the description of the processes involving heavy quarkonium.

Discrete symmetries employed to explain flavor mixing and mass hierarchies can be associated with an enlarged scalar sector which might lead to exotic Higgs decay modes. In this paper, we explore such a possibility in a scenario with $S_3$ flavor symmetry which requires three scalar $SU(2)$ doublets. The spectrum is fixed by minimizing the scalar potential, and we observe that the symmetry of the model leads to tantalizing Higgs decay modes potentially observable at the CERN Large Hadron Collider.

In this work we present 3-algebraic constructions and representations for three-dimensional $\mathcal{N}=5$ supersymmetric Chern-Simons theories, and show how they relate to theories with additional supersymmetries. The $\mathcal{N}=5$ structure constants give theories with $\mathrm{Sp}(2N)\times \mathrm{SO}(M)$ gauge symmetry, as well as more exotic symmetries known from gauged supergravity. We find explicit lifts from $\mathcal{N}=6$ to 8, and $\mathcal{N}=5$ to 6 and 8, for appropriate gauge groups.

The spin of black holes in black hole-neutron star binaries can have a strong influence on the merger dynamics and the post-merger state; a wide variety of spin magnitudes and orientations are expected to occur in nature. In this paper, we report the first simulations in full general relativity of black hole-neutron star mergers with misaligned black hole spin. We vary the spin magnitude from $a_{\mathrm{BH}}/M_{\mathrm{BH}}=0$ to $a_{\mathrm{BH}}/M_{\mathrm{BH}}=0.9$ for aligned cases, and we vary the misalignment angle from 0 to 80° for $a_{\mathrm{BH}}/M_{\mathrm{BH}}=0.5$. We restrict our study to $3:1$ mass-ratio systems and use a simple $\Gamma$-law equation of state. We find that the misalignment angle has a strong effect on the mass of the post-merger accretion disk, but only for angles greater than $\approx 40°$. Although the disk mass varies significantly with spin magnitude and misalignment angle, we find that all disks have very similar lifetimes $\approx 100\mathrm{ms}$. Their thermal and rotational profiles are also very similar. For a misaligned merger, the disk is tilted with respect to the final black hole’s spin axis. This will cause the disk to precess, but on a time scale longer than the accretion time. In all cases, we find promising setups for gamma-ray burst production: the disks are hot, thick, and hyperaccreting, and a baryon-clear region exists above the black hole.

We study a holographic cosmological model in which the infrared cutoff is set by the Ricci length and dark matter and dark energy do not evolve on their own but interact nongravitationally with each other. This greatly alleviates the cosmic coincidence problem because the ratio between both components does not vanish at any time. We constrain the model with observational data from supernovae, cosmic background radiation, baryon acoustic oscillations, gas mass fraction in galaxy clusters, the history of the Hubble function, and the growth function.

An unexpected distribution of temperatures in the CMB could be a sign of new physics. In particular, the existence of cosmic defects could be indicated by temperature discontinuities via the Kaiser-Stebbins effect. In this paper, we show how performing finite differences on a CMB map, with the noise regularized in harmonic space, may expose such discontinuities, and we report the results of this process on the 7-year Wilkinson Microwave Anisotropy Probe data.

We continue the study of covariant power-counting renormalizable gravity constrained by a scalar Lagrange multiplier. Lorentz-symmetry breaking is investigated in such a theory in comparison with the one in the ghost condensation model. Covariant power-counting renormalizable vector gravity which is invariant under $U(1)$ gauge symmetry is proposed. Several forms of vector Lagrange multiplier in this theory are discussed. It is shown that the covariant scalar/vector gravity under consideration may have a power-law or de Sitter accelerating cosmological solution corresponding to an inflationary era. The simplest black hole solution is obtained and dispersion relations for graviton are presented.

We examine the status of light neutralinos in an effective minimal supersymmetric extension of the standard model at the electroweak scale which was considered in the past and discussed in terms of the available data of direct searches for dark matter particles. Our reanalysis is prompted by new measurements at the Tevatron and $B$ factories which might potentially provide significant constraints on the minimal supersymmetric extension of the standard model. Here we examine in detail all these new data and show that the present published results from the Tevatron and $B$ factories have only a mild effect on the original light-neutralino population. This population, which fits quite well the DAMA/LIBRA annual modulation data, would also agree with the preliminary results of CDMS, CoGeNT, and CRESST, should these data, which are at present only hints of excesses of events over the expected backgrounds, be interpreted as authentic signals of dark matter. For the neutralino mass we find a lower bound of 7–8 GeV. Our results differ from some recent conclusions by other authors because of a few crucial points which we try to single out and elucidate.

Perturbative and nonperturbative results on the renormalization constants of the fermion field and the twist-2 fermion bilinears are presented with emphasis on the nonperturbative evaluation of the one-derivative twist-2 vector and axial-vector operators. Nonperturbative results are obtained using the twisted mass Wilson fermion formulation employing two degenerate dynamical quarks and the tree-level Symanzik improved gluon action. The simulations have been performed for pion masses in the range of about 450–260 MeV and at three values of the lattice spacing $a$ corresponding to $\beta =3.9$, 4.05, 4.20. Subtraction of $\mathcal{O}(a^2)$ terms is carried out by performing the perturbative evaluation of these operators at 1-loop and up to $\mathcal{O}(a^2)$. The renormalization conditions are defined in the $\mathrm{R}{\mathrm{I}}^{\prime }$-MOM scheme, for both perturbative and nonperturbative results. The renormalization factors, obtained for different values of the renormalization scale, are evolved perturbatively to a reference scale set by the inverse of the lattice spacing. In addition, they are translated to $\overline{\mathrm{MS}}$ at 2 GeV using 3-loop perturbative results for the conversion factors.

Dark matter annihilation to leptons, $\chi \chi \to \ell \overline{\ell }$, is necessarily accompanied by electroweak radiative corrections, in which a $W$ or $Z$ boson is radiated from a final-state particle. Given that the $W$ and $Z$ gauge bosons decay dominantly via hadronic channels, it is thus impossible to produce final-state leptons without accompanying protons, antiprotons, and gamma rays. Significantly, while many dark matter models feature a helicity-suppressed annihilation rate to fermions, radiating a massive gauge boson from a final-state fermion removes this helicity suppression, such that the branching ratios $\mathrm{Br}(\ell \nu W)$, $\mathrm{Br}({\ell }^{+}{\ell }^{-}Z)$, and $\mathrm{Br}(\nu \overline{\nu }Z)$ dominate over $\mathrm{Br}(\ell \overline{\ell })$. $W/Z$ bremsstrahlung thus allows indirect detection of many weakly interacting massive particle models that would otherwise be helicity suppressed, or $v^2$ suppressed. Antiprotons and even antideuterons become consequential final-state particles. This is an important result for future dark matter searches. We discuss the implications of $W/Z$ bremsstrahlung for “leptonic” dark matter models which aim to fit recent cosmic ray positron and antiproton data.

We have measured cross sections for forward neutron production from a variety of targets using proton beams from the Fermilab Main Injector. Measurements were performed for proton beam momenta of 58, 84, and $120\mathrm{GeV}/c$. The cross section dependence on the atomic weight ($A$) of the targets was found to vary as $A^{\alpha }$, where $\alpha$ is $0.46\pm 0.06$ for a beam momentum of $58\mathrm{GeV}/c$ and $0.54\pm 0.05$ for $120\mathrm{GeV}/c$. The cross sections show reasonable agreement with FLUKA and DPMJET Monte Carlos. Comparisons have also been made with the LAQGSM Monte Carlo.

We report a measurement of exclusive $e^{+}{e}^{-}\to D_s^{(*)+}{D}_s^{(*)-}$ cross sections as a function of center-of-mass energy near the $D_s^{(*)+}{D}_s^{(*)-}$ threshold with initial-state radiation. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of $967{\mathrm{fb}}^{-1}$.

In this paper we study half-BPS type IIB supergravity solutions with multiple ${\mathrm{AdS}}_3\times S^3\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] and have geometries given by the warped product of ${\mathrm{AdS}}_2\times S^2\times M_4$ over $\Sigma$, where $\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] are constructed introducing two meromorphic and two harmonic functions defined on $\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.

The black hole membrane paradigm states that a certain viscous membrane seems to be sitting on a stretched horizon of a black hole from the viewpoint of a distant observer. We show that the shear viscosity of the fictitious membrane can be reproduced by a highly excited string covering the stretched horizon except for a numerical coefficient.

By analyzing qualitative aspects of NS5-brane instanton corrections, we determine the topology of the hypermultiplet moduli space ${\mathcal{M}}_{\mathrm{H}}$ in Calabi-Yau compactifications of type II string theories at fixed value of the dilaton and of the Calabi-Yau metric. Specifically, we show that for fivebrane instanton couplings to be well-defined, translations along the intermediate Jacobian must induce nontrivial shifts of the Neveu-Schwarz axion which had thus far been overlooked. As a result, the Neveu-Schwarz axion parametrizes the fiber of a circle bundle, isomorphic to the one in which the fivebrane partition function is valued. In a companion paper, we go beyond the present analysis and take steps towards a quantitative description of fivebrane instanton corrections, using a combination of mirror symmetry, S-duality, topological string theory and twistor techniques.

The Fock quantization of fields propagating in cosmological spacetimes is not uniquely determined because of several reasons. Apart from the ambiguity in the choice of the quantum representation of the canonical commutation relations, there also exists a certain freedom in the choice of field: one can scale it arbitrarily absorbing background functions, which are spatially homogeneous but depend on time. Each nontrivial scaling turns out into a different dynamics and, in general, into an inequivalent quantum field theory. In this work we analyze this freedom at the quantum level for a scalar field in a nonstationary, homogeneous spacetime whose spatial sections have $S^3$ topology. A scaling of the configuration variable is introduced as part of a linear, time dependent canonical transformation in phase space. In this context, we prove in full detail a uniqueness result about the Fock quantization requiring that the dynamics be unitary and the spatial symmetries of the field equations have a natural unitary implementation. The main conclusion is that, with those requirements, only one particular canonical transformation is allowed, and thus only one choice of the field-momentum pair (up to irrelevant constant scalings). This complements another previous uniqueness result for scalar fields with a time varying mass on $S^3$, which selects a specific equivalence class of Fock representations of the canonical commutation relations under the conditions of a unitary evolution and the invariance of the vacuum under the background symmetries. In total, the combination of these two different statements of uniqueness picks up a unique Fock quantization for the system. We also extend our proof of uniqueness to other compact topologies and spacetime dimensions.

Two-timescale analysis has long been known as a particularly useful tool for studying dynamical systems with two different length scales. The parameter space of some accelerated worldlines shows such a situation. In this paper we find different sets of solutions for the equations of motion governing these worldlines by using two-timescale expansions. The general properties of these solutions are examined. This helps to derive simple schemes that reproduce secular effects of interacting forces. Rigorous prescriptions are given for computing the leading order motion which highlight the importance of dissipative terms in the force functions. In the end, we discuss some potential ambiguities in the two-timescale approach and possible deviations these prescriptions may have, from the exact worldlines.