The minimization of the Nambu-Goto action for a surface whose contour defines a circular Wilson loop of radius $a$ placed at a finite value of the coordinate orthogonal to the boundary is considered. This is done for asymptotically anti–de Sitter (AdS) spaces. The condensates of even dimension $n=2$ through 10 are calculated in terms of the coefficient of $a^n$ in the expansion of the on-shell subtracted Nambu-Goto action for small $a$. The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the condensates is universal in the sense that they only depend on the first coefficients of the difference with the AdS case.

Perturbative QCD (pQCD) running coupling $a(Q^2)$ ($\equiv {\alpha }_s(Q^2)/\pi$) is expected to get modified at low spacelike momenta $0<Q^2\lesssim 1{\mathrm{GeV}}^2$ so that, instead of having unphysical (Landau) singularities, it remains smooth and finite there, due to the infrared (IR) fixed point. This behavior is suggested by the Gribov-Zwanziger approach, Dyson-Schwinger equations and other functional methods, lattice calculations, light-front holographic mapping AdS/CFT modified by a dilaton background, and most of the analytic (holomorphic) QCD models. All such couplings $\mathcal{A}(Q^2)$ differ from the pQCD couplings $a(Q^2)$ at $|Q|\gtrsim 1\mathrm{GeV}$ by nonperturbative (NP) terms, typically by some power-suppressed terms $\sim 1/Q^{2N}$. Evaluations of low-energy physical QCD quantities in terms of such $\mathcal{A}(Q^2)$ couplings (with an IR fixed point) at a level beyond one loop are usually performed with a (truncated) power series in $\mathcal{A}(Q^2)$. We argue that such an evaluation is not correct, because the NP terms in general get out of control as the number of terms in the power series increases. The series consequently become increasingly unstable under the variation of the renormalization scale and have a fast asymptotic divergent behavior compounded by the renormalon problem. We argue that an alternative series in terms of logarithmic derivatives of $\mathcal{A}(Q^2)$ should be used. Furthermore, a Padé-related resummation based on this series gives results which are renormalization scale independent and show very good convergence. Timelike low-energy observables can be evaluated analogously, by using the integral transformation which relates the timelike observable with the corresponding spacelike observable.

Ratios of the true Yang-Mills vacuum wave functional, evaluated on any two field configurations out of a finite set of configurations, can be obtained from lattice Monte Carlo simulations. The method was applied some years ago to test various proposals for the vacuum wave functional in $2+1$ dimensions. In this article we use the same method to test our own proposal for the Yang-Mills ground state in $3+1$ dimensions, using two different types of test configurations: Abelian plane waves and non-Abelian constant field configurations. Our proposed vacuum state has the property of “dimensional reduction” at large scales, meaning that the (squared) vacuum state, evaluated on long-wavelength, large scale fluctuations, has the form of the Boltzmann weight for Yang-Mills theory in $D=3$ Euclidean dimensions. Our numerical results support this conjectured behavior. We also investigate the form of the ground state evaluated on shorter wavelength configurations.

In this article, we study the momentum dependence of the hadronic coupling constants $G_{B_c^{*}{B}_c\mathrm{\Upsilon }}$, $G_{B_c^{*}{B}_{c}J/\psi }$, $G_{B_c{B}_c\mathrm{\Upsilon }}$, and $G_{B_c{B}_{c}J/\psi }$ with the off-shell $\mathrm{{\rm Y}}$ and $J/\psi$ using the three-point QCD sum rules. Then we fit the hadronic coupling constants into analytical functions and extrapolate them into deep time-like regions to obtain the on-shell values $G_{B_c^{*}{B}_c\mathrm{\Upsilon }}(q^2=M_{\mathrm{\Upsilon }}^2)$, $G_{B_c^{*}{B}_{c}J/\psi }(q^2=M_{J/\psi }^2)$, $G_{B_c{B}_c\mathrm{\Upsilon }}(q^2=M_{\mathrm{\Upsilon }}^2)$, and $G_{B_c{B}_{c}J/\psi }(q^2=M_{J/\psi }^2)$ for the first time. These hadronic coupling constants can be taken as basic input parameters in phenomenological analyses.

We consider a simple extension of the Standard Model providing dark matter and a TeV-scale seesaw mechanism that also allows for viable leptogenesis. In addition to the Standard Model degrees of freedom, the model contains a neutrinophilic Higgs doublet, a scalar singlet, and six singlet fermions (including three right-handed Majorana neutrinos) that are charged under a local $U(1{)}^{\prime }$ gauge symmetry. We show how the $U(1{)}^{\prime }$ charge assignments and the choice of scalar potential can lead to a TeV-scale seesaw mechanism and $\mathcal{O}(1)$ neutrino Yukawa couplings in a straightforward way. While this scenario has all the ingredients one would expect for significant experimental signatures, including several new TeV-scale degrees of freedom, we find that most distinctive features associated with neutrino mass generation, leptogenesis and the dark sector are likely to remain inaccessible in the absence of additional lepton flavor symmetries.

In this work we generalize the results for the entropy spectra typically derived for black holes in general relativity to a generic horizon within the spherically symmetric (asymptotically flat and nonflat) space-times of more general theories of gravity. We use all the standard approaches—Bekenstein’s universal lower bound on the entropy transition, the highly damped quasinormal modes and reduced phase-space quantization—to derive the spectra. In particular, the three approaches show that the Bekenstein-like spectra for the horizon entropy is a robust result. Our results confirm the suggestion made relatively recently by an independent fourth argument by Kothawala et al. [Phys. Rev. D 78, 104018 (2008)].

Black objects lose their mass and angular momenta through evaporation by Hawking radiation, and the investigation of their time evolution has a long history. In this paper, we study this problem for a five-dimensional doubly spinning black ring. The black ring is assumed to emit only massless scalar particles. We consider a thin black ring with a small thickness parameter, $\lambda \ll 1$, which can be approximated by a boosted Kerr string locally. We show that a thin black ring evaporates with fixing its thickness parameter $\lambda$. Further, in the case of an Emparan-Reall black ring, we derive analytic formulas for the time evolution, which has one parameter to be evaluated numerically. We find that the lifetime of a thin black ring is shorter by a factor of $O({\lambda }^2)$ compared to a five-dimensional Schwarzschild black hole with the same initial mass. We also study detailed properties of the Hawking radiation from the thin black ring, including the energy and angular spectra of emitted particles.

We calculate the renormalized vacuum energy density for a massless scalar field confined between two nearby parallel plates formed by ideal uncharged conductors, placed very close to the surface of a rotating spherical gravitational source with mass $M$, radius $R$ and angular momentum $J$, at the equatorial region. We consider that the source rotates slowly and that the gravitational field is weak. Corrections to the Casimir energy density induced by the gravitational field generated by this source are calculated up to $M/R^2$ order. The results obtained show us that there is an important modification in the Casimir energy only in this order of approximation, which depends on the surface gravity as well as on the rotation of the source. Thermal corrections to the Casimir energy found are also calculated in all these orders.

We identify a signature of quantum gravitational effects that survives from the early Universe to the current era: Fluctuations of quantum fields as seen by comoving observers are significantly influenced by the history of the early Universe. In particular, we show how the existence (or not) of a quantum bounce leaves a trace in the background quantum noise that is not damped and would be non-negligible even nowadays. Furthermore, we estimate an upper bound for the typical energy and length scales where quantum effects are relevant. We discuss how this signature might be observed and therefore used to build falsifiability tests of quantum gravity theories.

Redshift-space distortions (RSDs) offer an attractive method to measure the growth of cosmic structure on large scales, and combining with the measurement of the cosmic expansion history, they can be used as cosmological tests of gravity. With the advent of future galaxy redshift surveys aiming at precisely measuring the RSD, an accurate modeling of RSD going beyond linear theory is a critical issue in order to detect or disprove small deviations from general relativity (GR). While several improved models of RSD have been recently proposed based on the perturbation theory (PT), the framework of these models heavily relies on GR. Here, we put forward a new PT prescription for RSD in general modified gravity models. As a specific application, we present theoretical predictions of the redshift-space power spectra in the $f(R)$ gravity model, and compare them with $N$-body simulations. Using the PT template that takes into account the effects of both modifications of gravity and RSD properly, we successfully recover the fiducial model parameter in $N$-body simulations in an unbiased way. On the other hand, we found it difficult to detect the scale dependence of the growth rate in a model-independent way based on GR templates.

A new Hamiltonian formulation of the minisuperspace cosmology following from the geodetic brane gravity model introduced by Regge and Teitelboim is presented. The model is considered in the framework of higher derivative theories which facilitates Hamiltonian formulation. The analysis is done using the equivalent first-order approach. The gauge generator containing the exact number of gauge parameters is constructed. Equivalence between the gauge and reparametrization symmetries has been demonstrated. Complete gauge fixed computations have been provided and formal quantization is done indicating the Wheeler DeWitt equation. Compatibility with existing results is shown.

The new observation of CDMS II favors low mass WIMPs. Taking the CDMS II new results as input, we consider a standard model (SM) singlet: the darkon as the dark matter (DM) candidate, which can be either a scalar, fermion, or vector. It is found that the simplest scenario of $\mathrm{DM}+\mathrm{SM}$ conflicts with the stringent constraint set by the LHC data. New physics beyond the SM is needed, and in this work, we discuss an extended standard model $S{U}_L(2)\otimes U_Y(1)\otimes U(1{)}^{\prime }$ where $U(1{)}^{\prime }$ only couples to the darkon. The new gauge symmetry is broken into $U_{em}(1)$ and two neutral bosons $Z^0$ and $Z^{\prime }$, which results in mixtures of $W_{\mu }^3$, $B_{\mu }$, and $X_{\mu }$. Following the literature and based on the CDMS data, we conduct a complete analysis to verify the validity of the model. The cross section of the elastic scattering between the darkon and nucleon is calculated, and the DM relic density is evaluated in the extended scenario. It is found that by considering the constraints from both the cosmology and collider experiments, one can reconcile all the presently available data only if $Z^{\prime }$ is lighter than $Z^0$.

Inspired by the observation of charmoniumlike state $X(3915)$, we explore the discovery potential of the $X(3915)$ production via meson photoproduction process. By investigating the $\gamma p\to J/\psi \omega p$ process including the $X(3915)$ signal and background contributions, we obtain the corresponding information of the cross section, the Dalitz plot, and the $J/\psi \omega$ invariant mass spectrum, which are helpful in further experimental study of $X(3915)$ via meson photoproduction.

Decays of beauty baryons to the $D^{0}p{h}^{-}$ and ${\mathrm{\Lambda }}_c^{+}{h}^{-}$ final states (where $h$ indicates a pion or a kaon) are studied using a data sample of $pp$ collisions, corresponding to an integrated luminosity of $1.0{\mathrm{fb}}^{-1}$, collected by the LHCb detector. The Cabibbo-suppressed decays ${\mathrm{\Lambda }}_b^0\to D^{0}p{K}^{-}$ and ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{K}^{-}$ are observed, and their branching fractions are measured with respect to the decays ${\mathrm{\Lambda }}_b^0\to D^{0}p{\pi }^{-}$ and ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{\pi }^{-}$. In addition, the first observation is reported of the decay of the neutral beauty-strange baryon ${\mathrm{\Xi }}_b^0$ to the $D^{0}p{K}^{-}$ final state, and a measurement of the ${\mathrm{\Xi }}_b^0$ mass is performed. Evidence of the ${\mathrm{\Xi }}_b^0\to {\mathrm{\Lambda }}_c^{+}{K}^{-}$ decay is also reported.

We consider M theory in the presence of $M$ parallel M5-branes probing a transverse $A_{N-1}$ singularity. This leads to a superconformal theory with (1,0) supersymmetry in six dimensions. We compute the supersymmetric partition function of this theory on a two-torus, with arbitrary supersymmetry preserving twists, using the topological vertex formalism. Alternatively, we show that this can also be obtained by computing the elliptic genus of an orbifold of recently studied M-strings. The resulting two-dimensional theory is a (4,0) supersymmetric quiver gauge theory whose Higgs branch corresponds to strings propagating on the moduli space of $SU{(N)}^{M-1}$ instantons on ${\mathbb{R}}^4$, where the right-moving fermions are coupled to a particular bundle.

The anapole moment is the only allowed electromagnetic moment for Majorana fermions. Fermionic dark matter acquiring an anapole can have a standard thermal history and be consistent with current direct detection experiments. In this paper, we calculate the collider monojet signatures of anapole dark matter and show that the current LHC results exclude anapole dark matter with mass less than 100 GeV, for an anapole coupling that leads to the correct thermal relic abundance.

Light pseudoscalars, or axionlike particles (ALPs), are much studied due to their potential relevance to the fields of particle physics, astrophysics, and cosmology. The most relevant coupling of ALPs from the viewpoint of current experimental searches is to the photon: in this work, we study the generation of this coupling as an effect of quantum corrections, which originated from an underlying Lorentz-violating background. Most interestingly, we show that the interaction so generated turns out to be Lorentz invariant, thus mimicking the standard ALP coupling to the photon that is considered in the experiments. This consideration implies that violations of spacetime symmetries, much studied as possible consequences of physics in very high energy scales, might infiltrate in other realms of physics in unsuspecting ways. Additionally, we conjecture that a similar mechanism can also generate Lorentz invariant couplings involving scalar particles and photons, playing a possible role in the phenomenology of Higgs bosons.

Mass, angular momentum, and charge inequalities for axisymmetric maximal time-symmetric initial data invariant under an action of U(1) group, in Einstein-Maxwell-axion-dilaton gravity being the low-energy limit of the heterotic string theory, is established. We assume that a data set with two asymptotically flat regions is given on a smooth simply connected manifold. We also pay attention to the area momentum charge inequalities for a closed orientable two-dimensional spacelike surface embedded in the spacetime of the considered theory.

We obtain a class of asymptotic flat or (anti)–de Sitter [(A)dS] hairy black holes in $D$-dimensional Einstein gravity coupled to a scalar with a certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a superpotential, and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to $D=11$ or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics is unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead of being some continuous integration constants.

Axionlike scalar fields and the Lane-Emden truncation of their periodic potential are analyzed as a model of dark matter halos. The apparent enhancement of infall velocities in merging clusters is intriguing: here it is tentatively explained via an intrinsic inelastic effect during relativistic soliton collisions.