We constrain the energy scale of noncommutativity of spacetime using cosmic microwave background data from PLANCK. We find that PLANCK data put the lower bound on the noncommutativity energy scale to about 20 TeV, which is about a factor of 2 larger than a previous constraint that was obtained using data from WMAP, ACBAR and CBI. We further show that inclusion of data of $E$ mode of cosmic microwave background polarization will not significantly change the constraint.

We examined whether significant constraints on matter-antimatter admixture can be derived from gamma-ray observations of colliding clusters of galaxies with Fermi-LAT. We selected ten known systems of colliding clusters of galaxies for the analysis and computed the upper bounds on matter-antimatter admixture in these systems, which range from $7\times 10^{-9}$ to $2\times 10^{-6}$. This allowed us to exclude a symmetric universe on scales of order $\sim 20\mathrm{Mpc}$ at the confidence level of 99.9%. Adopting the number of systems of colliding galaxy clusters from the Marenostrum Universe cosmological simulation, we checked if the Fermi-LAT second source catalog contains a sufficient number of gamma-ray sources to provide us with the required number of sources possibly associated with $p\overline{p}$ annihilation from cluster-anticluster collisions. We found that a matter-antimatter-symmetric universe is strongly ruled out on scales of order $\sim 20\mathrm{Mpc}$ if a matter-antimatter admixture in these bullet-like systems is of $f\gtrsim 10^{-5}$, and on scales of order $\sim 400\mathrm{Mpc}$ if $f\gtrsim 10^{-4}$.

This paper gives a complete characterization of the location of resonant orbits in a Kerr spacetime for all possible black hole spins and orbital parameter values. A resonant orbit in this work is defined as a geodesic for which the longitudinal and radial orbital frequencies are commensurate. Our analysis is based on expressing the resonance condition in its most symmetric form using Carlson’s elliptic integrals, which enable us to provide exact results together with a number of concise formulas characterizing the explicit dependence on the system parameters. The locations of resonant orbits identify regions where intriguing observable phenomena could occur in astrophysical situations when various sources of perturbation act on the binary system. Resonant effects may have observable implications for the inspirals of compact objects into a supermassive black hole. During a generic inspiral the slowly evolving orbital frequencies will pass through a series of low-order resonances where the ratio of orbital frequencies is equal to the ratio of two small integers. At these locations rapid changes in the orbital parameters could produce a measurable phase shift in the emitted gravitational and electromagnetic radiation. Resonant orbits may also capture gas or larger objects leading to further observable characteristic electromagnetic emission. According to the Kolmogorov-Arnold-Moser theorem, low-order resonant orbits demarcate the regions where the onset of geodesic chaos could occur when the Kerr Hamiltonian is perturbed. Perturbations are induced for example if the spacetime of the central object is non-Kerr, if gravity is modified, if the orbiting particle has large multipole moments, or if additional masses are nearby. We find that the $1/2$ and $2/3$ resonances occur at approximately 4 and 5.4 Schwarzschild radii ($R_s$) from the black hole’s event horizon. For compact object inspirals into supermassive black holes ($\sim {10}^6{M}_{\odot }$) this region lies within the sensitivity band of space-based gravitational wave detectors such as eLISA. When interpreted within the context of the supermassive black hole at the Galactic center, Sgr A*, this implies that characteristic length scales of $41\mu \mathrm{as}$ and $55\mu \mathrm{as}$ and time scales of 50 min and 79 min respectively should be associated with resonant effects if Sgr A* is nonspinning, while spin decreases these values by up to $\sim 32\%$ and $\sim 28\%$. These length scales are potentially resolvable with radio very-long-baseline interferometry measurements using the Event Horizon Telescope. We find that all low-order resonances are localized to the strong field region. In particular, for distances $r>50R_s$ from the black hole, the order of the resonances is sufficiently large that resonant effects of generic perturbations are not expected to lead to drastic changes in the dynamics. This fact guarantees the validity of using approximations based on averaging to model the orbital trajectory and frequency evolution of a test object in this region. Observing orbital motion in the intermediate region $50R_s<r<1000R_s$ is thus a “sweet spot” for systematically extracting the multipole moments of the central object by observing the orbit of a pulsar—since the object is close enough to be sensitive to the quadruple moment of the central object but far enough away not to be subjected to resonant effects.

We study a minimal extension of the Standard Model where a scalar field is coupled to the right-handed neutrino responsible for the seesaw mechanism for neutrino masses. In the absence of other couplings, below 8 TeV the scalar $A$ has a unique decay mode $A\to \nu \nu$, $\nu$ being the physical observed light neutrino state. Above 8 TeV (11 TeV), the 3-body (4-body) decay modes dominate. Imposing constraints on neutrino masses $m_{\nu }$ from atmospheric and solar experiments implies a long lifetime for $A$, much larger than the age of the Universe, making it a natural dark matter candidate. Its lifetime can be as large as ${10}^{29}\mathrm{seconds}$, and its signature below 8 TeV would be a clear monochromatic neutrino signal, which can be observed by ANTARES or IceCube. Under certain conditions, the scalar $A$ may be viewed as a Goldstone mode of a complex scalar field whose vacuum expectation value generates the Majorana mass for ${\nu }_R$. In this case, we expect the dark matter scalar to have a mass $\lesssim 10\mathrm{GeV}$.

A systematic analysis of the near-threshold enhancement in the $\overline{p}p$ invariant mass spectrum seen in the decay reactions $J/\psi \to x\overline{p}p$ and $\psi (3686)\to x\overline{p}p$ $(x=\gamma ,\omega ,\rho ,\pi ,\eta )$ is presented. The enhancement is assumed to be due to the $\overline{N}N$ final-state interaction (FSI) and the pertinent FSI effects are evaluated in an approach that is based on the distorted-wave Born approximation. For the $\overline{N}N$ interaction a recent potential derived within chiral effective field theory and fitted to results of a partial-wave analysis of $\overline{p}p$ scattering data is considered and, in addition, an older phenomenological model constructed by the Jülich group. It is shown that the near-threshold spectrum observed in various decay reactions can be reproduced simultaneously and consistently by our treatment of the $\overline{p}p$ FSI. It turns out that the interaction in the isospin-1 ${{}^{1}S}_0$ channel required for the description of the $J/\psi \to \gamma \overline{p}p$ decay predicts a $\overline{N}N$ bound state.

Traditional searches for R-parity conserving natural supersymmetry (SUSY) require large transverse mass and missing energy cuts to separate the signal from large backgrounds. SUSY models with compressed spectra inherently produce signal events with small amounts of missing energy that are hard to explore. We use this difficulty to motivate the construction of “deconstructed” transverse mass variables which are designed preserve information on both the norm and direction of the missing momentum. We demonstrate the effectiveness of these variables in searches for the pair production of supersymmetric top-quark partners which subsequently decay into a final state with an isolated lepton, jets and missing energy. We show that the use of deconstructed transverse mass variables extends the accessible compressed spectra parameter space beyond the region probed by traditional methods. The parameter space can further be expanded to neutralino masses that are larger than the difference between the stop and top masses. In addition, we also discuss how these variables allow for novel searches of single stop production, in order to directly probe unconstrained stealth stops in the small stop- and neutralino-mass regime. We also demonstrate the utility of these variables for generic gluino and stop searches in all-hadronic final states. Overall, we demonstrate that deconstructed transverse variables are essential to any search wanting to maximize signal separation from the background when the signal has undetected particles in the final state.

A conventional approach to precision calculations of Higgs boson observables uses quark masses $m_c$ and $m_b$ as inputs. However, quark masses are single numbers that hide a variety of low-energy data from which they are extracted, and also hide the various sources of theoretical uncertainties and correlations with additional input parameters such as ${\alpha }_s$. Higher-precision calculations, which are needed to give meaning to future measurements, require more direct engagement with the low-energy data in a global analysis. We present an initial calculation in this direction, which illustrates the procedure and reveals some of the theory uncertainties that challenge subpercent determinations of Higgs boson partial widths.

In this paper we build a holographic model of paramagnetism/antiferromagnetism phase transition, which is realized by introducing two real antisymmetric tensor fields coupling to the background gauge field strength and interacting with each other in a dyonic black brane background. In the case without an external magnetic field and in low temperatures, the magnetic moments condense spontaneously in an antiparallel manner with the same magnitude and the time reversal symmetry is also broken spontaneously (if the boundary spatial dimension is more than 2, spatial rotational symmetry is broken spontaneously as well), which leads to an antiferromagnetic phase. In the case with the weak external magnetic field, the magnetic susceptibility density has a peak at the critical temperature and satisfies the Curie-Weiss law in the paramagnetic phase of antiferromagnetism. In the strong external magnetic field case, there is a critical magnetic field $B_c$ in the antiferromagnetic phase: when the magnetic field reaches $B_c$, the system will return into the paramagnetic phase by a second order phase transition.

We construct new classes of exact cosmological solutions to five-dimensional Einstein-Maxwell-dilaton theory with two coupling constants for the dilaton-Maxwell term and the dilaton-cosmological constant term. All the solutions are nonstationary, and the solutions where both coupling constants are nonzero are almost regular everywhere. The size of the spatial section of the asymptotic metric shrinks to zero at early times and increases to infinitely large at very late times. The cosmological constant depends on the dilaton coupling constant and can take positive, zero, or negative values.

We study the stability under the perturbation and the related antievaporation of the Nariai space-time in bigravity. If we impose a specific condition for the solutions and parameters, we obtain asymptotically de Sitter space-time, and show the existence of the Nariai space-time as a background solution. Considering the perturbation around the Nariai space-time up to the first order, we investigate the behavior of the black hole horizon. We show that the antievaporation does not occur on the classical level in the bigravity.

Inhomogeneities associated with the cosmological QCD and electroweak phase transitions produce hydrodynamical perturbations, longitudinal sounds and rotations. It has been demonstrated by Hindmarsh et al. [Phys. Rev. Lett. 112, 041301 (2014)] that the sounds produce gravity waves well after the phase transition is over. We further argue that, under certain conditions, an inverse acoustic cascade may occur and move sound perturbations from the (UV) momentum scale at which the sound is originally produced to much smaller (IR) momenta. The weak turbulence regime of this cascade is studied via the Boltzmann equation, possessing stationary power and time-dependent self-similar solutions. We suggest certain indices for the strong turbulence regime as well, into which the cascade eventually proceeds. Finally, we point out that two on-shell sound waves can produce one on-shell gravity wave, and we evaluate the rate of the process using a standard sound loop diagram.

Observations of the extragalactic radio background have uncovered a significant isotropic emission across multiple frequencies spanning from 22 MHz to 10 GHz. The intensity of this nonthermal emission component significantly exceeds the expected contribution from known astrophysical sources. Interestingly, models have indicated that the annihilation of dark matter particles may reproduce both the flux and spectrum of the excess. However, the lack of a measurable anisotropy in the residual emission remains challenging for both dark matter and standard astrophysical interpretations of the ARCADE-2 data. We calculate the expected synchrotron anisotropy from dark matter annihilation and show that these models can produce very small anisotropies, though this requires galaxy clusters to have large substructure contributions and strong magnetic fields. We show that this constraint can be significantly relaxed, however, in scenarios where electrons produced via dark matter annihilation can be efficiently reaccelerated by Alfvén waves in the intra-Cluster medium. Our analysis indicates that any source capable of explaining the intensity and isotropy of the extragalactic radio excess must have a spatial extension far larger than typical for baryons in galaxies, hinting at a novel physics interpretation.

The distribution of canonical determinants in QCD is determined by means of chiral perturbation theory. For a nonzero quark charge the canonical determinants take complex values. In the dilute pion gas approximation, we compute all moments of the magnitude of the canonical determinants, as well as the first nonvanishing moments of the real and imaginary parts. The nontrivial cancellation between the real and the imaginary parts of the canonical determinants is derived and the signal to noise ratio is discussed. The analytical distributions are compared to lattice data. The average density of the magnitude of the canonical determinants is determined as well and is shown to be given by a variant of the log-normal distribution.

A study of charged-current muon neutrino scattering on hydrocarbon in which the final state includes a muon, at least one proton, and no pions is presented. Although this signature has the topology of neutrino quasielastic scattering from neutrons, the event sample contains contributions from quasielastic and inelastic processes where pions are absorbed in the nucleus. The analysis accepts events with muon production angles up to 70° and proton kinetic energies greater than 110 MeV. The cross section, when based completely on hadronic kinematics, is well described by a relativistic Fermi gas nuclear model including the neutrino event generator modeling for inelastic processes and particle transportation through the nucleus. This is in contrast to the quasielastic cross section based on muon kinematics, which is best described by an extended model that incorporates multinucleon correlations. This measurement guides the formulation of a complete description of neutrino-nucleus interactions that encompasses the hadronic as well as the leptonic aspects of this process.

We explicitly calculate the one-loop Kählerian effective potential for the supersymmetric topologically massive gauge theory in four dimensions that involves two gauge superfields, the usual scalar one and the spinor one originally introduced by Siegel, coupled to a chiral scalar matter.

We present here a relationship among massive self-dual models for spin-3 particles in $D=2+1$ via the Noether gauge embedment (NGE) procedure. Starting with a first-order model (in derivatives) $S_{\mathrm{SD}(1)}$ we have obtained a sequence of four self-dual models $S_{\mathrm{SD}(i)}$ where $i=1,2,3,4$. We demonstrate that the NGE procedure generates the correct action for the auxiliary fields automatically. We obtain the whole action for the fourth-order self-dual model including all the needed auxiliary fields to get rid of the ghosts of the theory.

We obtain a new exact solution of the 5D Einstein equations in vacuum describing a distorted Myers-Perry black hole with a single angular momentum. Locally, the solution is interpreted as a black hole distorted by a stationary $U(1)\times U(1)$ symmetric distribution of external matter. Technically, the solution is constructed by applying a twofold Bäcklund transformation on a 5D distorted Minkowski spacetime as a seed. The physical quantities of the solution are calculated, and a local Smarr-like relation on the black hole horizon is derived. It possesses the same form as the Smarr-like relation for the asymptotically flat Myers-Perry black hole. It is demonstrated that in contrast to the asymptotically flat Myers-Perry black hole, the ratio of the horizon angular momentum and the mass $J^2/M^3$ is unbounded, and can grow arbitrarily large. We study the properties of the ergoregion and the horizon surface. The external field does not influence the horizon topology. The horizon geometry however is distorted, and any regular axisymmetric geometry is possible.

Formal solutions to the mode equations for both spherically symmetric black holes and Bose-Einstein condensate acoustic black holes are obtained by writing the spatial part of the mode equation as a linear Volterra integral equation of the second kind. The solutions work for a massless minimally coupled scalar field in the $s$-wave or zero angular momentum sector for a spherically symmetric black hole and in the longitudinal sector of a one-dimensional Bose-Einstein condensate acoustic black hole. These solutions are used to obtain in a rigorous way analytic expressions for the scattering coefficients and gray-body factors in the zero frequency limit. They are also used to study the infrared behaviors of the symmetric two-point function and two functions derived from it: the point-split stress-energy tensor for the massless minimally coupled scalar field in Schwarzschild–de Sitter spacetime and the density-density correlation function for a Bose-Einstein condensate acoustic black hole.

We calculate the atmospheric neutrino fluxes in the energy range 100 GeV–10 PeV with the use of several known hadronic models and a few parametrizations of the cosmic-ray spectra which take into account the knee. The calculations are compared with the atmospheric neutrino measurements by Frejus, AMANDA, IceCube, and ANTARES. An analytic description is presented for the conventional (${\nu }_{\mu }+{\overline{\nu }}_{\mu }$) and (${\nu }_e+{\overline{\nu }}_e$) energy spectra, averaged over zenith angles, which can be used to obtain test data of the neutrino event reconstruction in neutrino telescopes. The sum of the calculated atmospheric ${\nu }_{\mu }$ flux and the IceCube best-fit astrophysical flux gives the evidently higher flux as compared to the IceCube59 data, giving rise the question concerning the hypothesis of the equal flavor composition of the high-energy astrophysical neutrino flux. Calculations show that the transition from the atmospheric electron neutrino flux to the predominance of the astrophysical neutrinos occurs at 30–100 TeV if the prompt neutrino component is taken into consideration. The neutrino flavor ratio, extracted from the IceCube data, does not tend to increase with the energy as is expected for the conventional neutrino flux in the energy range 100 GeV–30 TeV. A depression of the ratio $R_{{\nu }_{\mu }/{\nu }_e}$ possibly indicates that the atmospheric electron neutrino flux obtained in the IceCube experiment contains an admixture of the astrophysical neutrinos in the range 10–50 TeV.

The inclusion of aligned-spin effects in gravitational-wave search pipelines for neutron-star–black-hole binary coalescence has been shown to increase the astrophysical reach with respect to search methods where spins are neglected completely, under astrophysically reasonable assumptions about black-hole spins. However, theoretical considerations and population synthesis models suggest that many of these binaries may have a significant misalignment between the black-hole spin and the orbital angular momentum, which could lead to precession of the orbital plane during the inspiral and a consequent loss in detection efficiency if precession is ignored. This work explores the effect of spin misalignment on a search pipeline that completely neglects spin effects and on a recently developed pipeline that only includes aligned-spin effects. Using synthetic but realistic data, which could reasonably represent the first scientific runs of advanced-LIGO detectors, the relative sensitivities of both pipelines are shown for different assumptions about black-hole spin magnitude and alignment with the orbital angular momentum. Despite the inclusion of aligned-spin effects, the loss in signal-to-noise ratio due to precession can be as large as 40%, but this has a limited impact on the overall detection rate: even if precession is a predominant feature of neutron-star–black-hole binaries, an aligned-spin search pipeline can still detect at least half of the signals compared to an idealized generic precessing search pipeline.