In the energy range from a few TeV to 25 TeV, upper bounds on the dark matter decay rate into high-energy monochromatic neutrinos have recently become comparable to those on monochromatic gamma-ray lines. This implies the clear possibility of a future double “smoking gun” as evidence of the dark matter particle, from the observation of both a gamma and a neutrino line at the same energy. In particular, we show that a scenario where both lines are induced from the same dark matter particle decay leads to correlations that can already be tested. We study this “double monochromatic” scenario by considering the complete list of lowest-dimensional effective operators that could induce such a decay. Furthermore, we argue that, on top of lines from decays into two-body final states, three-body final states can also be highly relevant. In addition to producing a distinct hard photon spectrum, three-body final states also produce a linelike feature in the neutrino spectrum that can be searched for with neutrino telescopes.

The Telescope Array (TA) collaboration has reported a hotspot of 19 ultrahigh-energy cosmic rays (UHECRs). Using a universal model with one source and energy-dependent magnetic deflections, we show that the distribution of the TA hotspot events is consistent with a single source hypothesis, although multiple sources cannot be ruled out. The chance probability of this distribution arising from a homogeneous distribution is 0.2%. We describe a Monte Carlo Bayesian (MCB) inference approach, which can be used to derive parameters of the magnetic fields as well as the source coordinates, and we apply this method to the TA hotspot data, inferring the location of the likely source. We discuss possible applications of the same approach to future data.

Coherent radiation at radio frequencies from high-energy showers fully contained in a dense radio-transparent medium—like ice, salt, soil, or regolith—has been extensively investigated as a promising technique to search for ultrahigh-energy neutrinos. Additional emission in the form of transition radiation may occur when a neutrino-induced shower produced close to the Earth’s surface emerges from the ground into atmospheric air. We present the first detailed evaluation of transition radiation from high-energy showers crossing the boundary between two different media. We found that transition radiation is sizable over a wide solid angle and coherent up to $\sim 1\mathrm{GHz}$. These properties encourage further work to evaluate the potential of a large-aperture ultrahigh-energy neutrino experiment based on the detection of transition radiation.

Within the Dyson-Schwinger equation framework, a gluon propagator model incorporating a quark’s feedback through operator product expansion is introduced to investigate the QCD phase diagram in the temperature-chemical-potential ($T-\mu$) plane. Partial restoration of chiral symmetry at zero temperature and finite temperature are both studied, suggesting a first order phase transition point on the $\mu$ axis and a critical end point at $(T_E,{\mu }_E)/T_c=(0.85,1.11)$, where $T_c$ is the pseudocritical temperature. In addition, we find the pseudocritical line can be well parametrized with the curvature parameter $\kappa$ and a consistent decrease in $\kappa$, with more of the gluon propagator distributed to the quark’s feedback.

Within the framework of dispersion theory, we analyze the dipion transitions between the lightest $\mathrm{\Upsilon }$ states, $\mathrm{\Upsilon }(nS)\to \mathrm{\Upsilon }(mS)\pi \pi$ with $m<n\le 3$. In particular, we consider the possible effects of two intermediate bottomoniumlike exotic states $Z_b(10610)$ and $Z_b(10650)$. The $\pi \pi$ rescattering effects are taken into account in a model-independent way using dispersion theory. We confirm that matching the dispersive representation to the leading chiral amplitude alone cannot reproduce the peculiar two-peak $\pi \pi$ mass spectrum of the decay $\mathrm{\Upsilon }(3S)\to \mathrm{\Upsilon }(1S)\pi \pi$. The existence of the bottomoniumlike $Z_b$ states can naturally explain this anomaly. We also point out the necessity of a proper extraction of the coupling strengths for the $Z_b$ states to $\mathrm{\Upsilon }(nS)\pi$, which is only possible if a Flatté-like parametrization is used in the data analysis for the $Z_b$ states.

We present a unitary multichannel model for $\overline{K}N$ scattering in the resonance region that fulfills unitarity. It has the correct analytical properties for the amplitudes once they are extended to the complex $s$-plane and the partial waves have the right threshold behavior. To determine the parameters of the model, we have fitted single-energy partial waves up to $J=7/2$ and up to 2.15 GeV of energy in the center-of-mass reference frame obtaining the poles of the ${\mathrm{\Lambda }}^{*}$ and ${\mathrm{\Sigma }}^{*}$ resonances, which are compared to previous analyses. We provide the most comprehensive picture of the $S=-1$ hyperon spectrum to date. Important differences are found between the available analyses, making the gathering of further experimental information on $\overline{K}N$ scattering mandatory to make progress in the assessment of the hyperon spectrum.

The charge asymmetry in the production of top quark and antiquark pairs is measured in proton-proton collisions at a center-of-mass energy of 8 TeV. The data, corresponding to an integrated luminosity of $19.6{\mathrm{fb}}^{-1}$, were collected by the CMS experiment at the LHC. Events with a single isolated electron or muon, and four or more jets, at least one of which is likely to have originated from hadronization of a bottom quark, are selected. A template technique is used to measure the asymmetry in the distribution of differences in the top quark and antiquark absolute rapidities. The measured asymmetry is $A_c^y=[0.33\pm 0.26(\mathrm{stat})\pm 0.33(\mathrm{syst})]\%$, which is the most precise result to date. The results are compared to calculations based on the standard model and on several beyond-the-standard-model scenarios.

We report a measurement of the differential cross section of ${\pi }^0$ pair production in single-tag two-photon collisions, ${\gamma }^{*}\gamma \to {\pi }^0{\pi }^0$, in $e^{+}{e}^{-}$ scattering. The cross section is measured for $Q^2$ up to $30{\mathrm{GeV}}^2$, where $Q^2$ is the negative of the invariant mass squared of the tagged photon, in the kinematic range $0.5\mathrm{GeV}<W<2.1\mathrm{GeV}$ and $|\cos {\theta }^{*}|<1.0$ for the total energy and pion scattering angle, respectively, in the ${\gamma }^{*}\gamma$ center-of-mass system. The results are based on a data sample of $759{\mathrm{fb}}^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The transition form factor of the $f_0(980)$ and that of the $f_2(1270)$ with the helicity-0, -1, and -2 components separately are measured for the first time and are compared with theoretical calculations.

We consider a D1-brane as a natural probe of the group manifold with mixed three-form fluxes. We determine the Lax connection for a given theory. Then we switch to the canonical analysis and calculate the Poisson brackets between spatial components of Lax connections, and we argue for the integrability of a given theory.

Recently, there has been much interest in holographic computations of two-point nonequilibrium Green functions from anti–de Sitter- (AdS-)Vaidya backgrounds. In the strongly coupled quantum field theory on the boundary, the dual interpretation of the background is an equilibration process called a holographic quench. The two-dimensional AdS-Vaidya spacetime is a special case, dual to conformal quantum mechanics. We study how the quench is incorporated into a Hamiltonian $H+\theta (t)\mathrm{\Delta }H$ and into correlation functions. With the help of recent work on correlation functions in conformal quantum mechanics, we first rederive the known two-point functions, and then compute nonequilibrium three- and four-point functions. We also compute the three-point function Witten diagram in the two-dimensional AdS-Vaidya background, and find agreement with the conformal quantum mechanics result.

The Green’s function method is used to analyze the boundary effects produced by a Chern-Simons extension to electrodynamics. We consider the electromagnetic field coupled to a $\theta$ term that is piecewise constant in different regions of space, separated by a common interface $\mathrm{\Sigma }$, the $\theta$ boundary, model which we will refer to as $\theta$ electrodynamics. This model provides a correct low-energy effective action for describing topological insulators. Features arising due to the presence of the boundary, such as magnetoelectric effects, are already known in Chern-Simons extended electrodynamics, and solutions for some experimental setups have been found with a specific configuration of sources. In this work we construct the static Green’s function in $\theta$ electrodynamics for different geometrical configurations of the $\theta$ boundary, namely, planar, spherical and cylindrical $\theta$-interfaces. Also, we adapt the standard Green’s theorem to include the effects of the $\theta$ boundary. These are the most important results of our work, since they allow one to obtain the corresponding static electric and magnetic fields for arbitrary sources and arbitrary boundary conditions in the given geometries. Also, the method provides a well-defined starting point for either analytical or numerical approximations in the cases where the exact analytical calculations are not possible. Explicit solutions for simple cases in each of the aforementioned geometries for $\theta$ boundaries are provided. On the one hand, the adapted Green’s theorem is illustrated by studying the problem of a pointlike electric charge interacting with a planar topological insulator with prescribed boundary conditions. On the other hand, we calculate the electric and magnetic static fields produced by the following sources: (i) a pointlike electric charge near a spherical $\theta$ boundary, (ii) an infinitely straight current-carrying wire near a cylindrical $\theta$ boundary and (iii) an infinitely straight uniformly charged wire near a cylindrical $\theta$ boundary. Our generalization, when particularized to specific cases, is successfully compared with previously reported results, most of which have been obtained by using the method of images.

Matter neutrino resonances (MNRs) can occur in environments where the flux of electron antineutrinos is greater than the flux of electron neutrinos. These resonances may result in dramatic neutrino flavor transformation. Compact object merger disks are an example of an environment where electron antineutrinos outnumber neutrinos. We study MNR resonances in several such disk configurations and find two qualitatively different types of matter-neutrino resonances: a standard MNR and a symmetric MNR. We examine the transformation that occurs in each type of resonance and explore the consequences for nucleosynthesis.

We study the motion of neutral and charged spinning bodies in curved spacetime in the test-particle limit. We construct equations of motion using a closed covariant Poisson-Dirac bracket formulation that allows for different choices of the Hamiltonian. We derive conditions for the existence of constants of motion and apply the formalism to the case of spherically symmetric spacetimes. We show that the periastron of a spinning body in a stable orbit in a Schwarzschild or Reissner-Nordstrøm background not only precesses but also varies radially. By analyzing the stability conditions for circular motion we find the innermost stable circular orbit (ISCO) as a function of spin. It turns out that there is an absolute lower limit on the ISCOs for increasing prograde spin. Finally we establish that the equations of motion can also be derived from the Einstein equations using an appropriate energy-momentum tensor for spinning particles.

We investigate the propagation of scalar waves induced by matter sources in the context of scalar-tensor theories of gravity which include screening mechanisms for the scalar degree of freedom. The usual approach when studying these theories in the nonlinear regime of cosmological perturbations is based on the assumption that scalar waves travel at the speed of light. Within general relativity this approximation is valid and leads to no loss of accuracy in the estimation of observables. We find, however, that mass terms and nonlinearities in the equations of motion lead to propagation and dispersion velocities significantly different from the speed of light. As the group velocity is the one associated with the propagation of signals, a reduction of its value has direct impact on the behavior and dynamics of nonlinear structures within modified gravity theories with screening. For instance, the internal dynamics of galaxies and satellites submerged in large dark matter halos could be affected by the fact that the group velocity is smaller than the speed of light. It is therefore important, within such a framework, to take into account the fact that different parts of a galaxy will see changes in the environment at different times. A full nonstatic analysis may be necessary under those conditions.

Recent population synthesis simulations of Pop III stars suggest that the event rate of coalescence of $\sim 30M_{\odot }-30M_{\odot }$ binary black holes can be high enough for the detection by the second generation gravitational wave detectors. The frequencies of chirp signal as well as quasinormal modes are near the best sensitivity of these detectors so that it would be possible to confirm Einstein’s general relativity. Using the WKB method, we suggest that for the typical value of spin parameter $a/M\sim 0.7$ from numerical relativity results of the coalescence of binary black holes, the strong gravity of the black hole space-time at around the radius $2M$, which is just $\sim 1.17$ times the event horizon radius, would be confirmed as predicted by general relativity. The expected event rate with the signal-to-noise ratio $>35$ needed for the determination of the quasinormal mode frequency with a meaningful accuracy is $0.17-7.2\mathrm{events}{\mathrm{yr}}^{-1}$ [$({\mathrm{SFR}}_{\mathrm{p}}/(10^{-2.5}{\mathrm{M}}_{\odot }{\mathrm{yr}}^{-1}{\mathrm{Mpc}}^{-3}))·([{\mathrm{f}}_{\mathrm{b}}/(1+{\mathrm{f}}_{\mathrm{b}})]/0.33)$], where ${\mathrm{SFR}}_{\mathrm{p}}$ and ${\mathrm{f}}_{\mathrm{b}}$ are the peak value of the Pop III star formation rate and the fraction of binaries, respectively. As for the possible optical counterpart, if the merged black hole of mass $M\sim 60M_{\odot }$ is in the interstellar matter with $n\sim 100{\mathrm{cm}}^{-3}$ and the proper motion of the black hole is $\sim 1\mathrm{km}{\mathrm{s}}^{-1}$, the luminosity is $\sim {10}^{40}\mathrm{erg}{\mathrm{s}}^{-1}$ which can be detected up to $\sim 300\mathrm{Mpc}$, for example, by Subaru-HSC and LSST with the limiting magnitude 26.

We present an investigation of spinning black holes in Einstein–Gauss-Bonnet–dilaton (EGBd) theory. The solutions are found within a nonperturbative approach, by directly solving the field equations. These stationary axially symmetric black holes are asymptotically flat. They possess a nontrivial scalar field outside their regular event horizon. We present an overview of the parameter space of the solutions together with a study of their basic properties. We point out that the EGBd black holes can exhibit some physical differences when compared to the Kerr solution. For example, their mass is always bounded from below, while their angular momentum can exceed the Kerr bound. Also, in contrast to the Kerr case, the extremal solutions are singular, with the scalar field diverging on the horizon.

We present an improved numerical relativity (NR) calibration of the new effective-one-body (EOB) model for coalescing nonprecessing spinning black hole binaries recently introduced by Damour and Nagar [Phys. Rev. D 90, 044018 (2014)]. We do so by comparing the EOB predictions to both the phasing and the energetics provided by two independent sets of NR data covering mass ratios $1\le q\le 9.989$ and dimensionless spin range $-0.95\le \chi \le +0.994$. One set of data is a subset of the Simulating eXtreme Spacetimes (SXS) catalog of public waveforms; the other set consists of new simulations obtained with the Llama code plus Cauchy characteristic evolution. We present the first systematic computation of the gauge-invariant relation between the binding energy and the total angular momentum, $E_b(j)$, for a large sample of, spin-aligned, SXS and Llama data. The dynamics of the EOB model presented here involves only two free functional parameters, one [$a_6^c(\nu )$] entering the nonspinning sector, as a 5PN effective correction to the interaction potential, and one [$c_3({\tilde{a}}_1,{\tilde{a}}_2,\nu )]$ in the spinning sector, as an effective next-to-next-to-next-to-leading order correction to the spin-orbit coupling. These parameters are determined [together with a third functional parameter $\mathrm{\Delta }{t}_{\mathrm{NQC}}(\chi )$ entering the waveform] by comparing the EOB phasing with the SXS phasing, the consistency of the energetics being checked afterwards. The quality of the analytical model for gravitational wave data analysis purposes is assessed by computing the EOB/NR faithfulness. Over the NR data sample and when varying the total mass between 20 and 200 $M_{\odot }$ the EOB/NR unfaithfulness (integrated over the NR frequency range) is found to vary between 99.493% and 99.984% with a median value of 99.944%.

We report on an extensive study of the evolution of domain wall networks in Friedmann-Lemaître-Robertson-Walker universes by means of the largest currently available field-theory simulations. These simulations were done in ${4096}^3$ boxes and for a range of different fixed expansion rates, as well as for the transition between the radiation and matter eras. A detailed comparison with the velocity-dependent one-scale model shows that this cannot accurately reproduce the results of the entire range of simulated regimes if one assumes that the phenomenological energy loss and momentum parameters are constants. We therefore discuss how a more accurate modeling of these parameters can be done, specifically by introducing an additional mechanism of energy loss (scalar radiation, which is particularly relevant for regimes with relatively little damping) and a modified momentum parameter which is a function of velocity (in analogy to what was previously done for cosmic strings). We finally show that this extended model, appropriately calibrated, provides an accurate fit to our simulations.

We present a study of the fully relativistic spherical collapse in the presence of quintessence using on numerical relativity, following the method proposed by the authors in a previous article [Phys. Rev. D 91, 024025 (2015)]. We ascertain the validity of the method by studying the evolution of a spherically symmetric quintessence inhomogeneity on a de Sitter background and we find that it has an impact on the local expansion around the center of coordinates. We then proceed to compare the results of our method to those of the more largely adopted top-hat model. We find that quintessence inhomogeneities do build up under the effect that matter inhomogeneities have on the local space-time, yet remain very small due to the presence of momentum transfer from the over-dense to the background regions. We expect that these might have an even more important role in modified theories of gravitation.