We have studied the quasinormal modes of a massive scalar field coupling to Einstein’s tensor in the spacelike stretched ${\mathrm{AdS}}_3$ black hole spacetime. We find that both the right-moving and left-moving quasinormal frequencies depend not only on the warped parameter $v$ of the black hole, but also on the coupling between the scalar field and Einstein’s tensor. Moreover, we also discuss the warped AdS/CFT correspondence from the quasinormal modes and probe the effects of the coupling on the left and right conformal weights $h_L$ and $h_R$ of the operators dual to the scalar field in the boundary.

If the seed magnetic fields exist in the early Universe, tensor components of their anisotropic stresses are not compensated prior to neutrino decoupling, and the tensor metric perturbations generated from them survive passively. Consequently, due to the decay of these metric perturbations after recombination, the so-called integrated Sachs-Wolfe effect, the large-scale fluctuations of CMB radiation are significantly boosted. This kind of CMB anisotropy is called the “tensor passive mode.” Because these fluctuations deviate largely from the Gaussian statistics due to the quadratic dependence on the strength of the Gaussian magnetic field, not only the power spectrum but also the higher-order correlations have reasonable signals. With these motives, we compute the CMB bispectrum induced by this mode. When the magnetic spectrum obeys a nearly scale-invariant shape, we obtain an estimation of a typical value of the normalized reduced bispectrum as ${\ell }_1({\ell }_1+1){\ell }_3({\ell }_3+1)|b_{{\ell }_1{\ell }_2{\ell }_3}|\sim (130-6)\times {10}^{-16}(B_{1\mathrm{Mpc}}/4.7\mathrm{nG}{)}^6$, depending on the energy scale of the magnetic field production from ${10}^{14}\mathrm{GeV}$ to ${10}^3\mathrm{GeV}$. Here, $B_{1\mathrm{Mpc}}$ is the strength of the primordial magnetic field smoothed on 1 Mpc. From the above estimation and the current observational constraint on the primordial non-Gaussianity, we get a rough constraint on the magnetic field strength as $B_{1\mathrm{Mpc}}<2.6–4.4\mathrm{nG}$.

A nonlocal chiral quark model is consistently extended beyond mean field using a strict $1/N_c$ expansion scheme. The parameters of the nonlocal model are refitted so that the physical values of the pion mass and the weak pion decay constant are obtained. The size of the $1/N_c$ correction to the quark condensate is carefully studied and compared with the usual local Nambu–Jona-Lasinio model. It is found that even the sign of the corrections can be different. This can be attributed to the mesonic cutoff of the local model. The model is also applied to finite temperature. We find that the $1/N_c$ corrections dominate the melting of the chiral condensate at low temperatures, $T\lesssim 100\mathrm{MeV}$, in agreement with chiral perturbation theory. On the other hand, the relative importance of the $1/N_c$ corrections in the crossover regime depends on the parameter $T_0$ of the Polyakov-loop potential. For $T_0=270\mathrm{MeV}$, corresponding to a fit of lattice data for pure gluodynamics, the correction terms are large and lead to a lowering of the chiral phase-transition temperature in comparison with the mean-field result. Near the phase transition the $1/N_c$ expansion breaks down and a nonperturbative scheme is needed to include mesonic correlations in that regime. Lowering $T_0$ leads to a more rapid crossover even at the mean-field level and the unstable region for the $1/N_c$ corrections shrinks. For $T_0\lesssim 220\mathrm{MeV}$ the temperatures of deconfinement and chiral restoration are practically synchronized.

The associated production of a Higgs boson with a $b$ quark is a discovery channel for the lightest MSSM neutral Higgs boson. We consider the supersymmetric QCD contributions from squarks and gluinos and discuss the decoupling properties of these effects. A detailed comparison of our exact $\mathcal{O}({\alpha }_s)$ results with those of a widely used effective Lagrangian approach, the ${\Delta }_b$ approximation, is presented. The ${\Delta }_b$ approximation is shown to accurately reproduce the exact one-loop supersymmetric QCD result to within a few percent over a wide range of parameter space.

Positivity constraints, derived initially assuming parity conservation, for the inclusive reaction of the type $A(\mathrm{\text{spin}}1/2)+B(\mathrm{\text{spin}}1/2)\to C+X$, where the spins of both initial $\mathrm{\text{spin}}\mathrm{\text{−}}1/2$ particles can be in any possible directions and no polarization is observed in the final state, are generalized to the case of parity violation. By means of a systematic method, we obtain nontrivial bounds involving all the spin observables of the reaction and we discuss some relevant physics processes. Particularly, we discover a nontrivial positivity constraint for the processes $pp\to W^{\pm }/Z^0+X$ or $pp\to {\ell }^{\pm }+X$ where ${\ell }^{\pm }$ decayed from $W^{\pm }/Z^0$, which could be checked at the ongoing longitudinal spin program at Relativistic Heavy Ion Collider.

We study polarized and unpolarized semi-inclusive deep inelastic scattering processes, $\ell (S_{\ell })+p(S)\to {\ell }^{\prime }hX$, within a QCD parton model motivated by a generalized QCD factorization scheme. We take into account all transverse motions, of partons inside the initial proton and of hadrons inside the fragmenting partons and use the helicity formalism. The elementary interactions are computed at leading order with noncollinear exact kinematics, which introduces phases in the expressions of their helicity amplitudes. Several transverse momentum dependent distribution and fragmentation functions appear and contribute to the cross sections and to spin asymmetries. Our results agree with those obtained with different formalisms, showing the consistency of our approach. The full expression for single and double spin asymmetries $A_{S_{\ell }S}$ is derived. Simplified, explicit analytical expressions, convenient for phenomenological studies, are obtained assuming a factorized Gaussian dependence on intrinsic momenta for transverse momentum dependent functions.

The Belle Collaboration has reported measurements of the exclusive cross section for the processes $e^{+}{e}^{-}\to D^0{D}^{-}{\pi }^{+}$ and $e^{+}{e}^{-}\to D^0{D}^{*-}{\pi }^{+}$ over the center-of-mass energy range 4.0 GeV to 5.0 GeV. The resonant structure of the cross section suggests that the reactions go through the $\psi (4415)$ resonance. We study these reactions using a constituent quark model which successfully describes the $J^{PC}=1^{--}$ $c\overline{c}$ sector and show that the $\psi (4415)$ resonance alone as intermediate state is not able to reproduce the data. The inclusion of the $X(4360)$ resonance improves the agreement. Some comments about the $X(4660)$ are included.

We investigate the possibility of probing an anomalous $CP$-violating coupling in the $HWW$ vertex at the LHC. We consider the production of the Higgs boson in association with a $W$ and then decay via the $H\to WW$ channel taking into account the limits on the Higgs production cross section from the Tevatron. We select the same-sign dilepton final state arising from leptonic decays of two of the three $W$s and apply cuts required to suppress the standard model background. Several kinematical distributions and asymmetries that can be used to ascertain the presence of a nonzero anomalous coupling are presented. We find that, for Higgs mass in the range 130–150 GeV and anomalous couplings allowed by the Tevatron data, these distributions can be studied with an integrated luminosity of $30–50{\mathrm{fb}}^{-1}$ at the 14 TeV run. Attention is specifically drawn to some asymmetries that enable one to probe the real and imaginary parts (as well as their signs) of the anomalous coupling, in a complementary manner. We also explicitly demonstrate that showering and hadronization do not affect the utility of these variables, thus affirming the validity of parton-level calculations.

We present a new measurement of the inclusive forward-backward $t\overline{t}$ production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of $5.3{\mathrm{fb}}^{-1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$, recorded with the CDF-II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the $t\overline{t}$ rest frame, and in both cases are found to be consistent with $CP$ conservation under interchange of $t$ and $\overline{t}$. In the $t\overline{t}$ rest frame, the asymmetry is observed to increase with the $t\overline{t}$ rapidity difference, $\Delta y$, and with the invariant mass $M_{t\overline{t}}$ of the $t\overline{t}$ system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large $\Delta y$ and $M_{t\overline{t}}$. For $M_{t\overline{t}}\ge 450\mathrm{GeV}/c^2$, the parton-level asymmetry in the $t\overline{t}$ rest frame is $A^{t\overline{t}}=0.475\pm 0.114$ compared to a next-to-leading order QCD prediction of $0.088\pm 0.013$.

Gauge symmetries with nonuniversal couplings can manifest themselves in $e^{+}{e}^{-}$ collisions via generation-dependent deviations of leptonic observables from the standard model predictions. We analyze the deviations in terms of the lepton couplings to the extra neutral gauge boson and the polarizations of the positron and electron beams. We show how the proper manipulation of both the nonuniversal couplings and the applied beam polarization can result in considerable improvement in the differentiation of the corresponding models and in the identification reach of the extra nonuniversal gauge boson.

Adopting the phantom (ghost) scalar field description of dark energy, we construct a general class of exact interior solutions describing mixed relativistic stars containing both ordinary matter and dark energy in different proportions. The exterior solution that continuously matches the interior solutions is also found. Exact solutions describing extremal configurations with zero ordinary matter pressure are also constructed.

After considering a solitonic string moving in the Poincaré anti–de Sitter and two-dimensional sphere, we calculate the two-point correlation function of magnon and spike in the semiclassical limit without any explicit solution. We also calculate the three-point correlation functions between two heavy and one light operators. We find that the coupling between two heavy and one light operators in the string side is the exactly same as one obtained from the gauge theory by using the renormalization group analysis.

We present a nonperturbative proof of the no-hair theorems corresponding to scalar and Proca fields for stationary axisymmetric de Sitter black hole spacetimes. Our method also applies to asymptotically flat and under a reasonable assumption, to asymptotically anti-de Sitter spacetimes.

We present a detailed analytical analysis of the propagation of Bogoliubov phonons on top of Bose-Einstein condensates with spatial and temporal steplike discontinuities in the speed of sound in the hydrodynamic limit. We focus on some features in the correlations patterns, in particular, of density-density correlations. The application to the study of the Hawking signal in the formation of acoustic black hole-like configurations is also discussed.

According to the no-hair theorem, astrophysical black holes are uniquely characterized by their masses and spins and are described by the Kerr metric. Several parametric deviations from the Kerr metric have been suggested to study observational signatures in both the electromagnetic and gravitational-wave spectra that differ from the expected Kerr signals. Because of the no-hair theorem, however, such spacetimes cannot be regular everywhere outside the event horizons, if they are solutions to the Einstein field equations; they are often characterized by naked singularities or closed timelike loops in the regions of the spacetime that are accessible to an external observer. For observational tests of the no-hair theorem that involve phenomena in the vicinity of the circular photon orbit or the innermost stable circular orbit around a black hole, these pathologies limit the applicability of the metrics only to compact objects that do not spin rapidly. In this paper, we construct a Kerr-like metric which depends on a set of free parameters in addition to its mass and spin and which is regular everywhere outside of the event horizon. We derive expressions for the energy and angular momentum of a particle on a circular equatorial orbit around the black hole and compute the locations of the innermost stable circular orbit and the circular photon orbit. We demonstrate that these orbits change significantly for even moderate deviations from the Kerr metric. The properties of our metric make it an ideally suited spacetime to carry out strong-field tests of the no-hair theorem in the electromagnetic spectrum using the properties of accretion flows around astrophysical black holes of arbitrary spin.

Black hole entropy has been shown by ’t Hooft to diverge at the horizon. The region near the horizon is in a thermal state, so entropy is linear to energy which consequently also diverges. We find a similar divergence for the energy of the reduced density matrix of relativistic and nonrelativistic field theories, extending previous results in quantum mechanics. This divergence is due to an infinitely sharp division between the observable and unobservable regions of space, and it stems from the position/momentum uncertainty relation in the same way that the momentum fluctuations of a precisely localized quantum particle diverge. We show that when the boundary between the observable and unobservable regions is smoothed the divergence is tamed. We argue that the divergence of black hole entropy can also be interpreted as a consequence of position/momentum uncertainty, and that ’t Hooft’s brick wall tames the divergence in the same way, by smoothing the boundary.

We derive cosmological constraints on the annihilation cross section of dark matter with velocity-dependent structure, motivated by annihilating dark matter models through Sommerfeld or Breit-Wigner enhancement mechanisms. In models with an annihilation cross section increasing with decreasing dark matter velocity, a big-bang nucleosynthesis and cosmic microwave background give stringent constraints. Particularly, if the cross section is enhanced by a factor larger than ${10}^3$, the thermal relic scenario is excluded for the dark matter lighter than $\mathcal{O}(\mathrm{TeV})$.

Thermally relativistic flow with dissipation was analyzed by solving the rarefied supersonic flow of thermally relativistic matter around a triangle prism by Yano and Suzuki [Phys. Rev. D 83, 023517 (2011)], where the Anderson-Witting (AW) model was used as a solver. In this paper, we solve the same problem, which was analyzed by Yano and Suzuki, using the relativistic Boltzmann equation (RBE). To solve the RBE, the conventional direct simulation Monte Carlo method for the nonrelativistic Boltzmann equation is extended to a new direct simulation Monte Carlo method for the RBE. Additionally, we solve the modified Marle (MM) model proposed by Yano-Suzuki-Kuroda for comparisons. The solution of the thermally relativistic shock layer around the triangle prism obtained using the relativistic Boltzmann equation is considered by focusing on profiles of macroscopic quantities, such as the density, velocity, temperature, heat flux and dynamic pressure along the stagnation streamline (SSL). Differences among profiles of the number density, velocity and temperature along the SSL obtained using the RBE, the AW and MM. models are described in the framework of the relativistic Navier-Stokes-Fourier law. Finally, distribution functions on the SSL obtained using the RBE are compared with those obtained using the AW and MM models. The distribution function inside the shock wave obtained using the RBE does not indicate a bimodal form, which is obtained using the AW and MM models, but a smooth deceleration of thermally relativistic matter inside a shock wave.

The nonlinear dynamics of preheating after early-Universe inflation is often studied with lattice simulations. In this work I present a new lattice code HLattice. It differs from previous publicly available codes in the following three aspects: (i) A much higher accuracy is achieved with a modified sixth-order symplectic integrator; (ii) scalar, vector, and tensor metric perturbations in synchronous gauge and their feedback to the dynamics of scalar fields are all included; (iii) the code uses a projector that completely removes the scalar and vector components defined by the discrete spatial derivatives. Such a generic code can have a wide range of applications. As an example, gravity waves from preheating after inflation are calculated with a better accuracy.

Energetic antiprotons in cosmic rays can serve as an important indirect signature of dark matter. Conventionally, the antiproton flux from dark matter decay or annihilation is calculated by solving the transport equation with a space-independent diffusion coefficient within the diffusion zone of the galaxy. Antiproton sources outside the diffusion zone are ignored under the assumption that they propagate freely and escape. In reality, it is far more likely that the diffusion coefficient increases smoothly with distance from the disk, and the outlying part of the dark matter halo ignored in the conventional approach can be significant, containing as much as 90% of the galactic dark matter by mass in some models. We extend the conventional approach to address these issues. We obtain analytic approximations and numerical solutions for antiproton flux for a diffusion coefficient that increases exponentially with the distance from the disk, thereby including contributions from dark matter annihilation or decay in essentially the full dark matter halo. We find that the antiproton flux predicted in this model deviates from the conventional calculation for the same dark matter parameters by up to about 25%.