Loop corrections to observables in slow-roll inflation are found to diverge no worse than powers of the log of the scale factor, extending Weinberg’s theorem to quasisingle field inflation models. Demanding perturbation theory be valid during primordial inflation leads to constraints on the effective Lagrangian. This leads to some interesting constraints and coincidences on the landscape of inflationary vacua.

Coalescing binary black holes (BBHs) are among the most likely sources for the Laser Interferometer Gravitational-Wave Observatory (LIGO) and its international partners Virgo and KAGRA. Optimal searches for BBHs require accurate waveforms for the signal model and effectual template banks that cover the mass space of interest. We investigate the ability of the second-order post-Newtonian TaylorF2 hexagonal template placement metric to construct an effectual template bank, if the template waveforms used are effective one-body waveforms tuned to numerical relativity (EOBNRv2). We find that by combining the existing TaylorF2 placement metric with EOBNRv2 waveforms, we can construct an effectual search for BBHs with component masses in the range $3M_{\odot }\le m_1$, $m_2\le 25M_{\odot }$. We also show that the (computationally less expensive) TaylorF2 post-Newtonian waveforms can be used in place of EOBNRv2 waveforms when $M\lesssim 11.4M_{\odot }$. Finally, we investigate the effect of modes other than the dominant $l=m=2$ mode in BBH searches. We find that for systems with $(m_1/m_2)\le 1.68$ or inclination angle $\iota \le 0.31$ or $\iota \ge 2.68$ radians, there is no significant loss in the total possible signal-to-noise ratio due to neglecting modes other than $l=m=2$ in the template waveforms. For a source population uniformly distributed in spacial volume, over the entire sampled region of the component-mass space, the loss in detection rate (averaged over a uniform distribution of inclination angle and sky-location/polarization angles) remains below $\sim 11\%$. For binaries with high mass ratios and $0.31\le \iota \le 2.68$, including higher-order modes could increase the signal-to-noise ratio by as much as 8% in Advanced LIGO. Our results can be used to construct matched-filter searches in Advanced LIGO and Advanced Virgo.

Kelvin waves, or Kelvons, have been known for a long time as gapless excitations propagating along superfluid vortices. These modes can be interpreted as the Nambu-Goldstone excitations arising from the spontaneous breaking of the translational symmetry. Recently a different type of gapless excitation localized on strings—the so-called non-Abelian mode—attracted much attention in high-energy physics. We discuss their relevance in condensed matter physics. Non-Abelian rotational quasigapless excitations could appear on the mass vortices in the B phase of the superfluid ${}^3\mathrm{He}$, due to the fact that the order parameter in ${}^3\mathrm{He}$-B is tensorial. While the $U(1)$ rotational excitations are well established in vortices with asymmetric cores, the non-Abelian rotational excitations belonging to the same family were not considered.

Scalar-tensor theories of gravity are natural phenomenological alternatives to General Relativity, where the gravitational interaction is mediated by a scalar degree of freedom, besides the usual tensor gravitons. In regions of the parameter space of these theories where constraints from both solar system experiments and binary-pulsar observations are satisfied, we show that binaries of neutron stars present marked differences from General Relativity in both the late-inspiral and merger phases. In particular, phenomena related to the spontaneous scalarization of isolated neutron stars take place in the late stages of the evolution of binary systems, with important effects in the ensuing dynamics. We comment on the relevance of our results for the upcoming Advanced LIGO/Virgo detectors.

Recent results of the KASCADE-Grande experiment provided evidence for a mild knee-like structure in the all-particle spectrum of cosmic rays at $E={10}^{16.92\pm 0.10}\mathrm{eV}$, which was found to be due to a steepening in the flux of heavy primary particles. The spectrum of the combined components of light and intermediate masses was found to be compatible with a single power law in the energy range from ${10}^{16.3}$ to ${10}^{18}\mathrm{eV}$. In this paper, we present an update of this analysis by using data with increased statistics, originating both from a larger data set including more recent measurements and by using a larger fiducial area. In addition, optimized selection criteria for enhancing light primaries are applied. We find a spectral feature for light elements, namely, a hardening at $E={10}^{17.08\pm 0.08}\mathrm{eV}$ with a change of the power law index from $-3.25\pm 0.05$ to $-2.79\pm 0.08$.

A simple procedure within the $1/N_c$ expansion method where all the $N_c$ quarks are treated on the same footing has been found successful in describing mixed symmetric negative parity baryon states belonging to the $[\mathbf{70},{\ell }^{-}]$ multiplets of the $N=1$ and 3 bands. Presently it is applied to mixed symmetric positive parity $[\mathbf{70},0^{+}]$ and $[\mathbf{70},2^{+}]$ multiplets of the $N=2$ band. We search for the most dominant terms in the mass formula. The results are compared to those obtained in the procedure where the system is separated into a core and an excited quark. We find that both the spin and flavor operators of the entire system of $N_c$ quarks play dominant roles in describing the data, like for negative parity states. As a by-product we present the contribution of the leading spin-flavor singlet term as a function of the band number, which hints at distinct Regge trajectories for the symmetric and mixed symmetric states.

We briefly review the approach to dipole-dipole scattering in holographic QCD developed in G. Basar et al., Phys. Rev. D 85, 105005 (2012), based on a stringy Schwinger mechanism. The pomeron emerges through the exchange of closed strings between the dipoles and yields Regge behavior for the elastic amplitude. We calculate curvature corrections to this amplitude in both a conformal and confining background, identifying the holographic direction with the virtuality of the dipoles. The wee-dipole density is related to the string tachyon diffusion in both virtuality and the transverse directions. We give an explicit derivation of the dipole saturation momentum both in the conformal and confining background. Our holographic result for the dipole-dipole cross section and the wee-dipole density in the conformal limit are shown to be identical in form to the BFKL pomeron result when the noncritical string transverse dimension is $D_{\perp }=3$. The total dipole-dipole cross section is compared to DIS data from HERA.

Gluon and ghost propagators, obtained in Landau gauge from lattice simulations with two light two heavy dynamical quark flavors ($N_f=2+1+1$), are described here with a running formula including a four-loop perturbative expression and a nonperturbative operator product expansion correction dominated by the local operator $A^2$. The Wilson coefficients and their variation as a function of the coupling constant are extracted from the numerical data and compared with the theoretical expressions that, after being properly renormalized, are known at $\mathcal{O}({\alpha }^4)$. As ${\Lambda }_{\overline{\mathrm{MS}}}$ is also rather well known for $N_f=2+1+1$, this allows for a precise consistency test of the operator product expansion approach in the joint description of different observables.

We show that higher spin, maximal depth, partially massless systems defined in $d=4$ de Sitter space enjoy Maxwellian electric-magnetic duality. These photonlike models can also couple to charged matter.

We show the existence of a minimizing procedure for selecting a unique representative on the orbit of any given Riemann surface that contributes to the string partition function. As it must, the procedure reduces the string path integral to a final integration over a particular fundamental domain, selected by the choice of the minimizing functional. This construction somehow demystifies the Gribov question.

Recent numerical studies of the gluon propagator in the minimal Landau and Coulomb gauges in space-time dimension two, three, and four pose a challenge to the Gribov confinement scenario. In these gauges all configurations are transverse, $\partial ·A=0$, and lie inside the Gribov region $\Omega$, where the Faddeev-Popov operator, $M(A)=-{\partial }_{\mu }{D}_{\mu }(A)$, is positive, that is, $(\psi ,M(A)\psi )\ge 0$ for all $\psi$. We prove, without approximation, that for these gauges the continuum gluon propagator $D(k)$ in $\mathrm{SU}(N)$ gauge theory satisfies the bound $\frac{d-1}{d}\frac{1}{(2\pi {)}^d}\int d^{d}k\frac{D(k)}{k^2}\le N$. This holds for the Landau gauge, in which case $d$ is the dimension of space-time, and for the Coulomb gauge, in which case $d$ is the dimension of ordinary space and $D(k)$ is the instantaneous spatial gluon propagator. This bound implies that $\underset{k\to 0}{lim}{k}^{d-2}D(k)=0$, where $D(k)$ is the gluon propagator at momentum $k$, and consequently $D(0)=0$ in the Landau gauge in space-time $d=2$ and in the Coulomb gauge in space dimension $d=2$, but $D(0)$ may be finite in higher dimensions. These results are compatible with numerical studies of the Landau-and Coulomb-gauge propagator. In four-dimensional space-time a regularization is required, and we also prove an analogous bound on the lattice gluon propagator, $\frac{1}{d(2\pi {)}^d}{\int }_{-\pi }^{\pi }{d}^{d}k\frac{\sum _{\mu }{cos}^2(k_{\mu }/2)D_{\mu \mu }(k)}{4\sum _{\lambda }{sin}^2(k_{\lambda }/2)}\le N$. Here we have taken the infinite-volume limit of lattice gauge theory at fixed lattice spacing, and the lattice momentum componant $k_{\mu }$ is a continuous angle, $-\pi \le k_{\mu }\le \pi$. Unexpectedly, this implies a bound on a renormalization-group invariant that governs the overall normalization of the continuum gluon propagator in the minimum Landau and Coulomb gauges in four space-time dimensions, which, moreover, is compatible with the perturbative renormalization group when the theory is asymptotically free.

This letter presents a new, solely thermodynamical argument for considering the states of the quantum isolated horizon of a black hole as distinguishable. We claim that only if the states are distinguishable, the thermodynamic entropy is an extensive quantity and can be well-defined. To show this, we make a comparison with a classical ideal gas system whose statistical description makes only sense if an additional $1/N!$-factor is included in the state counting in order to cure the Gibbs paradox. The case of the statistical description of a quantum isolated horizon is elaborated, to make the claim evident.

In this paper we study the Higgs($h$)-radion($r$) system of the Randall-Sundum model where matter fermions and gauge fields live in the bulk while the Higgs boson resides on the infrared brane. We take into account the Kaluza-Klein loop correction to the $hVV$ and $rVV$ couplings where $V=g$, $\gamma$. Inspired by the LHC data in 2011 in which a hint of the Higgs boson has been seen at 125 GeV, we fix one of the mass eigenstates of the Higgs-radion mixed state at 125 GeV and scan over all the other parameters that have not been excluded by the 2011 Higgs search data. We find the regions of parameter space where the scalar particle at 125 GeV has a signal rate significantly larger or smaller than that of the Standard Model (SM) Higgs boson. The signal ratio $\mathrm{Br}(ZZ)/\mathrm{Br}(\gamma \gamma )$ also may deviate from that of the SM Higgs boson.

The Proca-Corben-Schwinger equations for a spin-1 particle with an anomalous magnetic moment are added by a term describing an electric dipole moment, then they are reduced to a Hamiltonian form, and finally they are brought to the Foldy-Wouthuysen representation. Relativistic equations of motion are derived. The needed agreement between quantum-mechanical and classical relativistic equations of motion is proved. The scalar and tensor electric and magnetic polarizabilities of pointlike spin-1 particles (W bosons) are calculated for the first time.

Geometric correlations between jets as part of hard processes or in addition to hard processes are key ingredients to many LHC analyses. Fox-Wolfram moments systematically describe these correlations in terms of spherical harmonics. These moments, computed either from the tagging jets or from all jets in each event, can significantly improve Higgs searches in weak boson fusion. Applications of Fox-Wolfram moments in LHC analyses obviously surpass jets as analysis objects, as well as Higgs searches in terms of analyses.

With the recent observation of nonzero ${\theta }_{13}$, five neutrino oscillation parameters are now known. By imposing four zeros in the Yukawa coupling matrix of the type I seesaw model, the number of parameters in the neutrino mass matrix is reduced to seven, and we are able to make predictions for the lightest neutrino mass, Dirac $CP$ phase, and neutrinoless double beta decay. Four texture zeros in the Yukawa coupling matrix is equivalent to either a single texture zero or a single cofactor zero for an off-diagonal element of the light neutrino mass matrix. We find strong similarities between single texture zero models with one mass ordering and single cofactor zero models with the opposite mass ordering. In the context of a specific class of single-flavor leptogenesis models, we find additional constraints on the parameter space.

In a recent paper we claimed that there are no slowly rotating, stationary, axisymmetric black holes in the infrared limit of Hořava-Lifshitz gravity, provided that they are regular everywhere apart from the central singularity. Here we point out a subtlety in the relation between Einstein-æther theory and the infrared limit of Hořava-Lifshitz gravity which was missed in our earlier derivation and drastically modifies our conclusion: our earlier calculations (which are otherwise technically correct) do not really imply that there are no slowly rotating black holes in Hořava-Lifshitz gravity, but that there are no slowly rotating black holes in the latter that are also solutions of Einstein-æther theory and vice versa. That is, even though the two theories share the static, spherically symmetric solutions, there are no slowly rotating black holes that are solutions to both theories. We proceed to generate slowly rotating black-hole solutions in the infrared limit of Hořava-Lifshitz gravity, and we show that the configuration of the foliation-defining scalar remains the same as in spherical symmetry, thus these black holes are expected to possess a universal horizon.

We study the transport coefficients, including the conductivities and shear viscosity of the nonrelativistic field theory dual to the Lifshitz black brane with multiple $U(1)$ gauge fields by virtue of the gauge/gravity duality. Focusing on the case of double $U(1)$ gauge fields, we systematically investigate the electric, thermal, and thermoelectric conductivities for the dual nonrelativistic field theory. In the large frequency regime, we find a nontrivial power law behavior in the electric alternating current conductivity when the dynamical critical exponent $z>1$ in ($2+1$)-dimensional field theory. The relations between this novel feature and the “symmetric hopping model” in condensed matter physics are discussed. In addition, we also show that the Kovtun-Starinets-Son bound for the shear viscosity to the entropy density is not violated by the additional $U(1)$ gauge fields and dilaton in the Lifshitz black brane.

We put to test the recently proposed nonlinear flux Ansatz for maximal supergravity in 11 dimensions, which gives the seven-dimensional flux in terms of the scalars and pseudoscalars of maximal $N=8$ supergravity, by considering a number of nontrivial solutions of gauged supergravity for which the higher-dimensional solutions are known. These include the ${\mathrm{G}}_2$ and $\mathrm{SU}(4{)}^{-}$ invariant stationary points. The examples considered constitute a very nontrivial check of the Ansatz, which it passes with remarkable success.