We provide an explicit construction of entangled states in a noncommutative space with nonclassical states, particularly with the squeezed states. Noncommutative systems are found to be more entangled than the usual quantum mechanical systems. The noncommutative parameter provides an additional degree of freedom in the construction by which one can raise the entanglement of the noncommutative systems to fairly higher values beyond the usual systems. Despite having classical-like behavior, coherent states in noncommutative space produce a small amount of entanglement and therefore they possess slight nonclassicality as well, which is not true for the coherent states of an ordinary harmonic oscillator.

We present the cosmological bounds on the thermal axion mass in an extended cosmological scenario in which the primordial power spectrum of scalar perturbations differs from the usual power-law shape predicted by the simplest inflationary models. The power spectrum is instead modeled by means of a “piecewise cubic Hermite interpolating polynomial” (pchip). When using cosmic microwave background measurements combined with other cosmological data sets, the thermal axion mass constraints are degraded only slightly. The addition of the measurements of ${\sigma }_8$ and ${\mathrm{\Omega }}_m$ from the 2013 Planck cluster catalog on galaxy number counts relaxes the bounds on the thermal axion mass, mildly favoring a $\sim 1\mathrm{eV}$ axion mass, regardless of the model adopted for the primordial power spectrum. However, in general, such a preference disappears if the sum of the three active neutrino masses is also considered as a free parameter in our numerical analyses, due to the strong correlation between the masses of these two hot thermal relics.

Two-point correlation functions of cosmic microwave background polarization provide a physically independent probe of the surprising suppression of correlations in the cosmic microwave background temperature anisotropies at large angular scales. We investigate correlation functions constructed from both the Q and U Stokes parameters and from the E and B polarization components. The dominant contribution to these correlation functions comes from local physical effects at the last scattering surface or from the epoch of reionization at high redshift, so all should be suppressed if the temperature suppression is due to an underlying lack of correlations in the cosmological metric perturbations larger than a given scale. We evaluate the correlation functions for the standard $\mathrm{\Lambda }\mathrm{CDM}$ cosmology constrained by the observed temperature correlation function, and compute statistics characterizing their suppression on large angular scales. Future full-sky polarization maps with minimal systematic errors on large angular scales will provide strong tests of whether the observed temperature correlation function is a statistical fluke or reflects a fundamental shortcoming of the standard cosmological model.

Vorticity generation in accretion disks around Schwarzschild and Kerr black holes is investigated in the context of magnetofluid dynamics derived for both General Relativity (GR) and modified gravity formulations. In both cases, the Kerr geometry leads to a “stronger” generation of vorticity than its Schwarzschild counterpart. Of the two principal sources, the relativistic drive peaks near the innermost stable circular orbit (isco), whereas the baroclinic drive dominates at larger distances. Consequences of this new relativistic vorticity source are discussed in several astrophysical settings.

The BES III Collaboration has recently observed a vector resonance in the ${\chi }_{c0}\omega$ channel, at a mass of about 4220 MeV, named $Y(4220)$. Hints of a similar structure appear in the $h_c{\pi }^{+}{\pi }^{-}$ channel. We find that the two observations are likely due to the same state, which we identify with one of the expected diquark-antidiquark resonances with orbital quantum number $L=1$. This assignment fulfills heavy quark spin conservation. The measured branching ratio of the $Y(4220)$ into ${\chi }_{c0}\omega$ and $h_c{\pi }^{+}{\pi }^{-}$ is compatible with the prediction for such a tetraquark state.

We study the vacuum alignment of the top-mode pseudo-Nambu-Goldstone boson Higgs (TMpNGBH) model, which has recently been proposed as a variant of the top-quark condensate model in light of the 126 GeV Higgs boson discovered at the LHC. It is shown that the vacuum of the model, determined from the one-loop effective potential with all the explicit breaking effects included, realizes the electroweak symmetry breaking with the appropriate breaking scale. Phenomenologies of two characteristic particles in the TMpNGBH model, namely the $CP$-odd partner of the Higgs ($A_t^0$) and the vectorlike partner of the top quark ($t^{\prime }$), are also studied based on the newly identified vacuum.

Many new physics models contain new particles that interact with the Higgs boson. These particles could be produced at the LHC via gluon-gluon fusion with an off-shell Higgs and, if charged under a gauge group, also via gluon-gluon fusion with an off-shell $Z$ boson and the Drell-Yan process. We consider in this paper simplified scenarios where the Standard Model is extended by one scalar or fermionic field that interacts with the Higgs boson, and we evaluate the impact of the Higgs interaction on the production of the exotic particles at the LHC. This analysis applies, in particular, to TeV-scale seesaw scenarios of neutrino mass generation.

Recently hints of lepton flavor nonuniversality emerged when the BABAR collaboration observed deviations from the standard model predictions in $R(D^{(*)})\equiv \mathcal{B}(\overline{B}\to D^{(*)+}{\tau }^{-}{\overline{\nu }}_{\tau })/\mathcal{B}(\overline{B}\to D^{(*)+}{\ell }^{-}{\overline{\nu }}_{\ell })$ ($\ell =e,\mu$). Another test of this nonuniversality can be in the semileptonic ${\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_c\tau {\overline{\nu }}_{\tau }$ decay. In this paper we present predictions for this decay in the standard model and in the presence of new physics operators with different Lorentz structures. We present the most general fourfold angular distribution for this decay including new physics. For phenomenology, we focus on predictions for the decay rate and the differential distribution in the momentum transfer squared $q^2$. In particular, we calculate $R_{{\mathrm{\Lambda }}_b}=\frac{BR[{\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_c\tau {\overline{\nu }}_{\tau }]}{BR[{\mathrm{\Lambda }}_b\to {\mathrm{\Lambda }}_c\ell {\overline{\nu }}_{\ell }]}$ where $\ell$ represents $\mu$ or $e$, and find the standard model prediction to be around 0.3 while the new physics operators can increase or slightly decrease this value.

Discovering dark matter at high-energy colliders continues to be a compelling and well-motivated possibility. Weakly interacting massive particles are a particularly interesting class in which the dark matter particles interact with the standard model weak gauge bosons. Neutralinos are a prototypical example that arise in supersymmetric models. In the limit where all other superpartners are decoupled, it is known that for relic density motivated masses, the rates for neutralinos are too small to be discovered at the Large Hadron Collider (LHC), but that they may be large enough to observe at 100 TeV. In this work we perform a careful study in the vector boson fusion channel for pure winos and pure Higgsinos. We find that given a systematic uncertainty of 1% (5%), with $3000{\mathrm{fb}}^{-1}$, the LHC is sensitive to winos of 240 GeV (125 GeV) and Higgsinos of 125 GeV (55 GeV). A future 100 TeV collider would be sensitive to winos of 1.1 TeV (750 GeV) and Higgsinos of 530 GeV (180 GeV) with a 1% (5%) uncertainty, also with $3000{\mathrm{fb}}^{-1}$.

XEFT is a low-energy effective field theory for charm mesons and pions that provides a systematically improvable description of the $X(3872)$ resonance. A Galilean-invariant formulation of XEFT is introduced to exploit the fact that mass is very nearly conserved in the transition $D^{*0}\to D^0{\pi }^0$. The transitions $D^{*0}\to D^0{\pi }^0$ and $X\to D^0{\overline{D}}^0{\pi }^0$ are described explicitly in XEFT. The effects of the decay $D^{*0}\to D^0\gamma$ and of short-distance decay modes of the $X(3872)$, such as $J/\psi {\pi }^{+}{\pi }^{-}$, can be taken into account by using complex on-shell renormalization schemes for the $D^{*0}$ propagator and for the $D^{*0}{\overline{D}}^0$ propagator in which the positions of their complex poles are specified. Galilean-invariant XEFT is used to calculate the $D^{*0}{\overline{D}}^0$ scattering length to next-to-leading order. Galilean invariance ensures the cancellation of ultraviolet divergences without the need for truncating an expansion in powers of the ratio of the pion and charm meson masses.

We report a measurement of the ${\nu }_{\mu }$ charged current quasielastic cross-sections on carbon in the T2K on-axis neutrino beam. The measured charged current quasielastic cross-sections on carbon at mean neutrino energies of 1.94 GeV and 0.93 GeV are $(11.95\pm 0.19(\text{stat}{)}_{-1.47}^{+1.82}(\text{syst}))\times 10^{-39}{\mathrm{cm}}^2/\text{neutron}$, and $(10.64\pm 0.37(\text{stat}{)}_{-1.65}^{+2.03}(\text{syst}))\times 10^{-39}{\mathrm{cm}}^2/\text{neutron}$, respectively. These results agree well with the predictions of neutrino interaction models. In addition, we investigated the effects of the nuclear model and the multi-nucleon interaction.

The luminosity of fading type Ia supernovae is governed by radioactive decays of ${}^{56}\mathrm{Ni}$ and ${}^{56}\mathrm{Co}$. The decay rates are proportional to the Fermi coupling constant $G_{\mathrm{F}}$ and, therefore, are determined by the vacuum expectation value $v$ of the Brout-Englert-Higgs field. We use publicly available sets of light curves of type Ia supernova at various redshifts to constrain possible spacetime variations of the ${}^{56}\mathrm{Ni}$ decay rate. The resulting constraint is not very tight; however, it is the only direct bound on the variation of the decay rate for redshifts up to $z\sim 1$. We discuss potential applications of the result to searches for nonconstancy of $G_{\mathrm{F}}$ and $v$.

We consider the timelike version of warped anti–de Sitter space (WAdS), which corresponds to the three-dimensional section of the Gödel solution of four-dimensional cosmological Einstein equations. This geometry presents closed timelike curves (CTCs), which are inherited from its four-dimensional embedding. In three dimensions, this type of solution can be supported without matter provided the graviton acquires mass. Here, among the different ways to consistently give mass to the graviton in three dimensions, we consider the parity-even model known as new massive gravity (NMG). In the bulk of timelike ${\mathrm{WAdS}}_3$ space, we introduce defects that, from the three-dimensional point of view, represent spinning massive particlelike objects. For this type of source, we investigate the definition of quasilocal gravitational energy as seen from infinity, far beyond the region where the CTCs appear. We also consider the covariant formalism applied to NMG to compute the mass and the angular momentum of spinning particlelike defects and compare the result with the one obtained by means of the quasilocal stress tensor. We apply these methods to special limits in which the ${\mathrm{WAdS}}_3$ solutions coincide with locally ${\mathrm{AdS}}_3$ and locally ${\mathrm{AdS}}_2\times \mathbb{R}$ spaces. Finally, we make some comments about the asymptotic symmetry algebra of asymptotically ${\mathrm{WAdS}}_3$ spaces in NMG.

Continuing work initiated in earlier publications [T. Ichita et al., Phys. Rev. D 83, 084026 (2011); K. Yamada and H. Asada, Phys. Rev. D 86, 124029 (2012)], we examine the post-Newtonian (PN) effects on the stability of the triangular solution in the relativistic three-body problem for general masses. For three finite masses, a condition for stability of the triangular solution is obtained at the first post-Newtonian (1PN) order, and it recovers previous results for the PN restricted three-body problem when one mass goes to zero. The stability regions still exist even at the 1PN order, though the PN triangular configuration for general masses is less stable than the PN restricted three-body case as well as the Newtonian one.

Using a framework based on the $1+3$ formalism, we show that a source represented by a geodesic, dissipative, rotational dust, endowed with axial and reflection symmetry, violates regularity conditions at the center of the fluid distribution unless the dissipative flux vanishes. In this latter case, the vorticity also must vanish, and the resulting spacetime is Friedman-Robertson-Walker. Therefore, it does not produce gravitational radiation.

The gravitational self-force (GSF) and post-Newtonian (PN) schemes are complementary approximation methods for modeling the dynamics of compact binary systems. Comparison of their results in an overlapping domain of validity provides a crucial test for both methods and can be used to enhance their accuracy, e.g. via the determination of previously unknown PN parameters. Here, for the first time, we extend such comparisons to noncircular orbits—specifically, to a system of two nonspinning objects in a bound (eccentric) orbit. To enable the comparison we use a certain orbital-averaged quantity $⟨U⟩$ that generalizes Detweiler’s redshift invariant. The functional relationship $⟨U⟩({\mathrm{\Omega }}_r,{\mathrm{\Omega }}_{\varphi })$, where ${\mathrm{\Omega }}_r$ and ${\mathrm{\Omega }}_{\varphi }$ are the frequencies of the radial and azimuthal motions, is an invariant characteristic of the conservative dynamics. We compute $⟨U⟩({\mathrm{\Omega }}_r,{\mathrm{\Omega }}_{\varphi })$ numerically through linear order in the mass ratio $q$, using a GSF code which is based on a frequency-domain treatment of the linearized Einstein equations in the Lorenz gauge. We also derive $⟨U⟩({\mathrm{\Omega }}_r,{\mathrm{\Omega }}_{\varphi })$ analytically through 3PN order, for an arbitrary $q$, using the known near-zone 3PN metric and the generalized quasi-Keplerian representation of the motion. We demonstrate that the $\mathcal{O}(q)$ piece of the analytical PN prediction is perfectly consistent with the numerical GSF results, and we use the latter to estimate yet unknown pieces of the 4PN expression at $\mathcal{O}(q)$.

We explore whether a new method to solve the constraints of Einstein’s equations can be applied to provide initial data for black holes. We show that this method, which does not involve elliptic equations, can be successfully applied to a nonlinear perturbation of a Schwarzschild black hole by establishing the well-posedness of the resulting constraint problem. We discuss its possible generalization to the boosted, spinning multiple black hole problem.

Gravitational-wave radiometry is a powerful tool by which weak signals with unknown signal morphologies are recovered through a process of cross correlation. Radiometry has been used, e.g., to search for persistent signals from known neutron stars such as Scorpius X-1. In this paper, we demonstrate how a more ambitious search—for persistent signals from unknown neutron stars—can be efficiently carried out using folded data, in which an entire $\sim$year-long observing run is represented as a single sidereal day. The all-sky, narrowband radiometer search described here will provide a computationally tractable means to uncover gravitational-wave signals from unknown, nearby neutron stars in binary systems, which can have modulation depths of $\approx 0.1–2\mathrm{Hz}$. It will simultaneously provide a sensitive search algorithm for other persistent, narrowband signals from unexpected sources.

We consider a model of the early Universe which consists of two scalar fields: the inflaton and a second field which drives the stabilization of the Planck mass (or gravitational constant). We show that the nonminimal coupling of this second field to the Ricci scalar sources a nonadiabatic pressure perturbation. By performing a fully numerical calculation, we find, in turn, that this boosts the amplitude of the primordial power spectrum after inflation.