We continue our study of quenched disorder in holographic systems, focusing on the effects of mild electric disorder. By studying the renormalization group evolution of the disorder distribution at subleading order in perturbations away from the clean fixed point, we show that electric disorder is marginally relevant in ($2+1$)-dimensional holographic conformal field theories.

In this paper, we develop a systematic technique to regularize double summations of Landau levels and analytically evaluate the photon vacuum polarization at an external magnetic field. The final results are described by Lerch transcendent $\mathrm{\Phi }(z,s,v)$ or its $z$ derivation. We find that the tensor of vacuum polarization is split into not only longitudinal and transverse parts but also another mixture component. The results remain gauge covariant as required by the Ward identity. We obtain a complete expression of the magnetized photon vacuum polarization at any kinematic regime and any strength of magnetic field for the first time. In the weak $B$ fields, after canceling out a logarithmic counterterm, all three scalar functions are limited to the usual photon polarization tensor without turning on a magnetic field. In the strong $B$ fields, the calculations under the lowest Landau level approximation are only valid at the region $M^2\gg q_{\parallel }^2$, but not correct when $q_{\parallel }^2\gg M^2$, where an imaginary part has been missed. It reminds us that a recalculation of the gap equation under a full consideration of all Landau levels will be necessary in the near future.

The neutrino emission characteristics of the first full-scale three-dimensional supernova simulations with sophisticated three-flavor neutrino transport for three models with masses 11.2, 20, and $27M_{\odot }$ are evaluated in detail. All the studied progenitors show the expected hydrodynamical instabilities in the form of large-scale convective overturn. In addition, the recently identified lepton-number emission self-sustained asymmetry (LESA) phenomenon is generic for all our cases. Standing accretion-shock instability (SASI) activity appears in the 20 and $27M_{\odot }$ cases, partly in the form of a spiral mode, inducing large but direction- and flavor-dependent modulations of neutrino emission. These modulations can be clearly identified in the existing IceCube and future Hyper-Kamiokande detectors, depending on the distance and detector location relative to the main standing accretion-shock instability sloshing direction.

We follow the Chumbes–Holf da Silva–Hott mechanism to study the (quasi)localization of the $U(1)$ gauge field on the Bloch brane. The localization and resonances of the $U(1)$ gauge field are discussed for four kinds of Bloch brane solutions: the original and generalized Bloch brane solutions, as well as the degenerate Bloch brane solutions I and II. With the Chumbes–Holf da Silva–Hott mechanism, we find that the mass spectrum of the gauge field Kaluza-Klein modes is continuous and there is no tachyonic mode. The zero mode is localized on all the branes and there are resonant Kaluza-Klein modes on the degenerate Bloch branes.

If the source of the reported 3.5 keV x-ray line is a sterile neutrino, comprising an $\mathcal{O}(1)$ fraction of the dark matter (DM), then it exhibits the property that its mass times mixing angle is $\sim \text{few}\times {10}^{-2}\mathrm{eV}$, a plausible mass scale for the active neutrinos. This property is a common feature of Dirac neutrino mixing. We present a framework that dynamically produces light active and keV sterile Dirac neutrinos, with appropriate mixing angles to be the x-ray line source. The central idea is that the right-handed active neutrino is a composite state, while elementary sterile neutrinos gain keV masses similarly to the quarks in extended technicolor. The entire framework is fixed by just two dynamical scales and may automatically exhibit a warm dark matter (WDM) production mechanism—dilution of thermal relics from late decays of a heavy composite neutrino—such that the keV neutrinos may comprise an $\mathcal{O}(1)$ fraction of the DM. In this framework, the WDM is typically quite cool and within structure formation bounds, with temperature $\sim \text{few}\times {10}^{-2}{T}_{\nu }$ and free-streaming length $\sim \mathrm{few}\mathrm{kpc}$. A toy model that exhibits the central features of the framework is also presented.

Hypergravity is the theory in which the graviton, of spin-2, has a supersymmetric partner of spin-$5/2$. There are “no-go” theorems that prevent interactions in these higher spin theories. However, it appears that one can circumvent them by bringing in an infinite tower of higher spin fields. With this possibility in mind, we study herein the electric-magnetic duality invariance of hypergravity. The analysis is carried out in detail for the free theory of the spin-$(2,5/2)$ multiplet, and it is indicated how it may be extended to the infinite tower of higher spins. Interactions are not considered. The procedure is the same that was employed recently for the spin-$(3/2,2)$ multiplet of supergravity. One introduces new potentials (“prepotentials”) by solving the constraints of the Hamiltonian formulation. In terms of the prepotentials, the action is written in a form in which its electric-magnetic duality invariance is manifest. The prepotential action is local, but the spacetime invariance is not manifest. Just as for the spin-2 and spin-$(3/2,2)$ cases, the gauge symmetries of the prepotential action take a form similar to those of the free conformal theory of the same multiplet. The automatic emergence of gauge conformal invariance, out of demand for manifest duality invariance, is yet more evidence of the subtle interplay between duality invariance and spacetime symmetry. We also compare and contrast the formulation with that of the analogous spin-$(1,3/2)$ multiplet.

In this work we consider thermodynamic geometries defined as Hessians of different potentials and derive some useful formulas that show their complementary role in the description of thermodynamic systems with 2 degrees of freedom that show ensemble nonequivalence. From the expressions derived for the metrics, we can obtain the curvature scalars in a very simple and compact form. We explain here the reason why each curvature scalar diverges over the line of divergence of one of the specific heats. This application is of special interest in the study of changes of stability in black holes as defined by Davies. From these results we are able to prove on a general footing a conjecture first formulated by Liu, Lü, Luo, and Shao stating that different Hessian metrics can correspond to different behaviors in the various ensembles. We study the case of two thermodynamic dimensions. Moreover, comparing our result with the more standard turning point method developed by Poincaré, we obtain that the divergence of the scalar curvature of the Hessian metric of one potential exactly matches the change of stability in the corresponding ensemble.

We study the thermodynamics in the grand canonical ensemble of $D$-dimensional charged Gauss-Bonnet-AdS black holes in the extended phase space. We find that the usual small-large black hole phase transition, which exhibits analogy with the van der Waals liquid-gas system, holds in five-dimensional spherical charged Gauss-Bonnet-AdS black holes when its potential is fixed within the range $0<\mathrm{\Phi }<\frac{\sqrt{3}\pi }{4}$. For the other higher dimensional and topological charged Gauss-Bonnet-AdS black holes, there is no such phase transition. In the limiting case, Reissner-Nordstrom AdS black holes, with vanishing Gauss-Bonnet parameter, there is no critical behavior in the grand canonical ensemble. This result holds independent of the spacetime dimensions and topologies. We also examine the behavior of physical quantities in the vicinity of the critical point in the five-dimensional spherical charged Gauss-Bonnet-AdS black holes.

Excision techniques are used in order to deal with black holes in numerical simulations of Einstein’s equations and consist in removing a topological sphere containing the physical singularity from the numerical domain, applying instead appropriate boundary conditions at the excised surface. In this work we present recent developments of this technique in the case of constrained formulations of Einstein’s equations and for spherically symmetric spacetimes. We present a new set of boundary conditions to apply to the elliptic system in the fully constrained formalism of Bonazzola et al. [Phys. Rev. D 70, 104007 (2004)], at an arbitrary coordinate sphere inside the apparent horizon. Analytical properties of this system of boundary conditions are studied and, under some assumptions, an exponential convergence toward the stationary solution is exhibited for the vacuum spacetime. This is verified in numerical examples, together with the applicability in the case of the accretion of a scalar field onto a Schwarzschild black hole. We also present the successful use of the excision technique in the collapse of a neutron star to a black hole, when excision is switched on during the simulation, after the formation of the apparent horizon. This allows the accretion of matter remaining outside the excision surface and for the stable long-term evolution of the newly formed black hole.

In this paper we demonstrate an efficient method for including both CMB temperature and polarization data in optimal non-Gaussian estimators. The method relies on orthogonalizing the multipoles of the temperature and polarization maps and results in a reduction by a factor of over 3 the terms required to calculate the estimator. The method is illustrated with the modal method applied to bispectrum estimation via the CMB with the trispectrum included as an appendix. However, the method is quite general and can be applied to any optimal bispectrum or trispectrum estimator including the Komatsu-Spergel-Wandelt, binned and wavelet approaches. It would also be applicable to any situation where multiple data sets with known correlations are being considered.

We consider the backreaction of the long wavelength tensor modes produced during a slow-roll inflationary regime driven by a single scalar field in a spatially flat Friedmann-Lemaître-Robertson-Walker background geometry. We investigate the effects on nonlocal observables such as the effective (averaged) expansion rate and equation of state at second order in cosmological perturbation theory. The coupling between scalar and tensor perturbations induces at second-order new tensor backreaction terms beyond the one already present in a de Sitter background. We analyze in detail the effects seen by the class of observers comoving with the inflaton field (taken as a clock) and the class of free-falling observers. In both cases the quantum backreaction is at least $1/\epsilon$ (with $\epsilon$ the slow-roll parameter) larger than the one which can be naively inferred from a de Sitter background. In particular, we compute the effect for a free massive inflaton model and obtain in both cases a quantum correction on the background expansion rate of the order of $H^4/(m^2{M}_{\text{Pl}}^2)$. A short discussion on the issue of the breakdown of perturbation theory is given.

Recently a new extended nonlinear massive gravity model has been proposed which includes the $F(R)$ modifications to the de Rham–Gabadadze–Tolley model. We follow the $F(R)$ nonlinear massive gravity and study its implications on cosmological evolutions. We derive the critical points of the cosmic system and study the corresponding kinetics by performing the phase-plane analysis.

We consider the two scalar field cosmology in a Friedmann Robertson Walker spatially flat spacetime where the scalar fields interact both in the kinetic part and the potential. We apply the Noether point symmetries in order to define the interaction of the scalar fields. We use the point symmetries in order to write the field equations in the normal coordinates, and we find that the Lagrangian of the field equations which admits at least three Noether point symmetries describes linear Newtonian systems. Furthermore, by using the corresponding conservation laws we find exact solutions of the field equations. Finally, we generalize our results to the case of $N$ scalar fields interacting both in their potential and their kinematic part in a flat Friedmann Robertson Walker background.

The detection of B-modes in the cosmic microwave background (CMB) polarization by the BICEP2 experiment, if interpreted as evidence for a primordial gravitational wave background, has enormous ramifications for cosmology and physics. It is crucial to test this hypothesis with independent measurements. A gravitational wave background leads to B-modes in galaxy shape correlations (shear) both through lensing and tidal alignment effects. Since the systematics and foregrounds of galaxy shapes and CMB polarization are entirely different, a detection of a cross correlation between the two observables would provide conclusive proof for the existence of a primordial gravitational wave background. We find that upcoming weak lensing surveys will be able to detect the cross correlation between B-modes of the CMB and galaxy shapes. However, this detection is not sufficient to confirm or falsify the hypothesis of a primordial origin for CMB B-mode polarization.

Radiative losses have traditionally been neglected in the calculation of thermal noise of transmissive optical elements because for the most commonly used geometries they are small compared to losses due to thermal conduction. We explore the use of such transmissive optical elements in extremely noise-sensitive environments such as the arm cavities of future gravitational-wave interferometers. This drives us to a geometry regime where radiative losses are no longer negligible. In this paper we derive the thermorefractive noise associated with such radiative losses and compare it to other known sources of thermal noise.

The search for gravitational waves is one of today’s major scientific endeavors. A gravitational wave can interact with matter by exciting vibrations of elastic bodies. Earth itself is a large elastic body whose so-called normal-mode oscillations ring up when a gravitational wave passes. Therefore, precise measurement of vibration amplitudes can be used to search for the elusive gravitational-wave signals. Earth’s free oscillations that can be observed after high-magnitude earthquakes have been studied extensively with gravimeters and low-frequency seismometers over many decades leading to invaluable insight into Earth’s structure. Making use of our detailed understanding of Earth’s normal modes, numerical models are employed for the first time to accurately calculate Earth’s gravitational-wave response, and thereby turn a network of sensors that so far has served to improve our understanding of Earth, into an astrophysical observatory exploring our Universe. In this paper, we constrain the energy density of gravitational waves to values in the range 0.035–0.15 normalized by the critical energy density of the Universe at frequencies between 0.3 and 5 mHz, using ten years of data from the gravimeter network of the Global Geodynamics Project that continuously monitors Earth’s oscillations. This work is the first step towards a systematic investigation of the sensitivity of gravimeter networks to gravitational waves. Further advances in gravimeter technology could improve sensitivity of these networks and possibly lead to gravitational-wave detection.

In this paper, the relations of four different susceptibilities (i.e., the chiral susceptibility, the fermion number susceptibility, the thermal susceptibility, and the staggered spin susceptibility) are investigated both in and beyond the chiral limit. To this end, we numerically solve the finite-temperature version of the truncated Dyson-Schwinger equations for the fermion and boson propagator. It is found that, in the chiral limit, the four susceptibilities give the same critical temperature and signal a typical second order phase transition. But the situation changes beyond the chiral limit: the critical temperatures from the chiral and the thermal susceptibilities are different, which shows that to define a critical region instead of an exclusive point for crossover might be a more suitable choice. Meanwhile, both the fermion number and the staggered spin susceptibilities have no singular behaviors any more; this may mean that they are no longer available to describe the crossover properties of the system.

We discuss the realization of a vanishing effective Higgs potential at the Planck scale, which is required by the multiple-point criticality principle (MPCP), in the standard model with singlet scalar dark matter and a right-handed neutrino. We find the scalar dark matter and the right-handed neutrino play crucial roles for realization of the MPCP, where a neutrino Yukawa becomes effective above the Majorana mass of the right-handed neutrino. Once the top mass is fixed, the MPCP at the (reduced) Planck scale and the suitable dark matter relic abundance determine the dark matter mass, $m_S$, and the Majorana mass of the right-handed neutrino, $M_R$, as $8.5(8.0)\times {10}^2\mathrm{GeV}\le m_S\le 1.4(1.2)\times {10}^3\mathrm{GeV}$ and $6.3(5.5)\times {10}^{13}\mathrm{GeV}\le M_R\le 1.6(1.2)\times {10}^{14}\mathrm{GeV}$ within current experimental values of the Higgs and top masses. This scenario is consistent with current dark matter direct search experiments and will be checked by future experiments such as LUX with further exposure and/or the XENON1T.

We investigate the Standard Model Higgs boson production in $e^{-}\gamma$ collisions. The electroweak one-loop contributions to the scattering amplitude for $e^{-}\gamma \to e^{-}H$ are calculated and expressed in analytical form. We analyze the cross section for the Higgs boson production in $e^{-}\gamma$ collisions for each combination of polarizations of the initial electron and photon beams. The feasibility of observing the Higgs boson in the $e^{-}+\gamma \to e^{-}+b+\overline{b}$ channel is examined.