We address the issues of the scattering of massless planar scalar waves by an acoustic black hole in neo-Newtonian hydrodynamics. We then compute the differential cross section through the use of the partial wave approach in the neo-Newtonian theory which is a modification of the usual Newtonian theory that correctly incorporates the effects of pressure. We mainly show that the scattering of planar waves leads to a modified analogue Aharonov-Bohm effect due to a nontrivial response of the parameters defining the equation of state.

In a recent paper [M. Assanioussi, A. Dapor, and J. Lewandowski, Phys. Lett. B 751, 302 (2015)] a general mechanism for the emergence of cosmological spacetime geometry from a quantum gravity setting was devised and a departure from standard dispersion relations for an elementary particle was predicted. We elaborate here on this approach extending the results obtained in that paper and showing that generically such a framework will not lead to higher order modified dispersion relations in the matter sector. Furthermore, we shall discuss possible phenomenological constraints to this scenario showing that spacetime will have to be classical to a very high degree by now in order to be consistent with current observations.

A simple idea of relating the loop quantum gravity (LQG) and loop quantum cosmology (LQC) degrees of freedom is introduced and used to define a relatively robust interface between these theories in context of toroidal Bianchi I model. The idea is an expansion of the construction originally introduced by Ashtekar and Wilson-Ewing and relies on explicit averaging of a certain subclass of spin networks over the subgroup of the diffeomorphisms remaining after the gauge fixing used in homogeneous LQC. It is based on the set of clearly defined principles and thus is a convenient tool to control the emergence and behavior of the cosmological degrees of freedom in studies of dynamics in canonical LQG. The constructed interface is further adapted to isotropic spacetimes. Relating the proposed LQG-LQC interface with some results on black hole entropy suggests a modification to the area gap value currently used in LQC.

In this paper we study a spin foam model for 4D Riemannian gravity, and propose a new way of imposing the simplicity constraints that uses the recently developed holomorphic representation. Using the power of the holomorphic integration techniques, and with the introduction of two new tools, the homogeneity map and the loop identity, for the first time we give the analytic expressions for the behavior of the spin foam amplitudes under four-dimensional Pachner moves. It turns out that this behavior is controlled by an insertion of nonlocal mixing operators. In the case of the 5–1 move, the expression governing the change of the amplitude can be interpreted as a vertex renormalization equation. We find a natural truncation scheme that allows us to get an invariance up to an overall factor for the 4–2 and 5–1 moves, but not for the 3–3 move. The study of the divergences shows that there is a range of parameter space for which the 4–2 move is finite while the 5–1 move diverges. This opens up the possibility to recover diffeomorphism invariance in the continuum limit of spin foam models for 4D quantum gravity.

The inhomogeneous chiral phase is discussed in QCD at finite temperature and/or density. We study the phase diagram on the density-temperature plane by taking into account the effect of the current quark mass by a variational method. We demonstrate that our framework well describes the inhomogeneous phase over the whole phase region.

We study the $F$-wave $\overline{c}s$ heavy meson doublets $(2^{+},3^{+})$ and $(3^{+},4^{+})$. They have large orbital excitations $L=3$, and may be good challenges (tests) for theoretical studies. To study them we use the method of QCD sum rule in the framework of heavy quark effective theory. Their masses are predicted to be $m_{(2^{+},3^{+})}=(3.45\pm 0.25,3.50\pm 0.26)\mathrm{GeV}$ and $m_{(3^{+},4^{+})}=(3.20\pm 0.22,3.26\pm 0.23)\mathrm{GeV}$, with mass splittings $\mathrm{\Delta }{m}_{(2^{+},3^{+})}=m_{3^{+}}-m_{2^{+}}=0.046\pm 0.030\mathrm{GeV}$ and $\mathrm{\Delta }{m}_{(3^{+},4^{+})}=0.053\pm 0.044\mathrm{GeV}$, respectively. We note that this is a pioneering work and these results are provisional.

Within a nonlinear chiral Lagrangian framework, the underlying mixings among quark-antiquark, four-quark and glue components of $f_0(1500)$ and $f_0(1710)$ are studied in a global picture that includes all isosinglet scalar mesons below 2 GeV. The quark components are introduced in the Lagrangian in terms of two separate nonets (a quark-antiquark nonet and a four-quark nonet) which can mix with each other and with a scalar glueball. An iterative Monte Carlo simulation is developed to study the 14 free parameters of the Lagrangian by a simultaneous fit to more than 20 experimental data and constraints on the mass spectrum, decay widths, and decay ratios of the isosinglet scalars below 2 GeV. Moreover, constraints on the mass spectrum and decay widths of isodoublet and isovector scalars below 2 GeV as well as pion-pion scattering amplitude are also taken into account. In the leading order of the model and within the overall experimental uncertainties, the ranges of variation of the model parameters are determined. This leads to a set of points in the 14-dimensional parameter space at which the overall disagreement with experiment is no larger than the overall experimental uncertainties. The insights gained in this global picture, due to the complexities of the mixings as well as the experimental uncertainties, are mainly qualitative but are relatively robust, and reveal that the lowest scalar glueball hides between $f_0(1500)$ and $f_0(1710)$, resulting in a considerable mixing with various quark components of these two states. The overall current experimental and theoretical uncertainties do not allow us to pin down the exact glue components of isosinglet states; nevertheless it is shown that the $f_0(1500)$ and $f_0(1710)$ have the highest glue component. While this global study does not allow precision predictions for each individual state, it provides useful “family” correlations among the isosinglet states that are found insightful in probing the substructure of scalars, in general, and the isosinglets, in particular. Specifically, a close correlation between the substructure of isosinglets below and above 1 GeV is observed. It is shown that as the simulations approach the limit where the $f_0(500)$ and $f_0(980)$ become the two isosinglet members of an ideally mixed two-quark two-antiquark nonet (which is widely believed to be a good approximation), the $f_0(1500)$ develops a large glue component. The overall estimate of the scalar glueball mass is found to be $1.58\pm 0.18\mathrm{GeV}$.

We study the ultraviolet to infrared evolution and nonperturbative behavior of a simple set of asymptotically free chiral gauge theories with an $\mathrm{SU}(N)$ gauge group and an anomaly-free set of $n_{S_k}$ copies of chiral fermions transforming as the symmetric rank-$k$ tensor representation, $S_k$, and $n_{{\overline{A}}_{\ell }}$ copies of fermions transforming according to the conjugate antisymmetric rank-$\ell$ tensor representation, ${\overline{A}}_{\ell }$, of this group with $k$, $\ell \ge 2$. As part of our study, we prove a general theorem guaranteeing that a low-energy effective theory resulting from the dynamical breaking of an anomaly-free chiral gauge theory is also anomaly-free. We analyze the theories with $k=\ell =2$ in detail and show that there are only a finite number of these. Depending on the specific theory, the ultraviolet to infrared evolution may lead to a non-Abelian Coulomb phase, or may involve confinement with massless composite fermions, or fermion condensation with dynamical gauge and global symmetry breaking. We show that $S_k{\overline{A}}_k$ chiral gauge theories with $k\ge 3$ are not asymptotically free. We also analyze theories with fermions in $S_k$ and ${\overline{A}}_{\ell }$ representations of $\mathrm{SU}(N)$ with $k\ne \ell$ and $k$, $\ell \ge 2$.

Extensions of Einstein gravity with quadratic curvature terms in the action arise in most effective theories of quantized gravity, including string theory. This article explores the set of static, spherically symmetric and asymptotically flat solutions of this class of theories. An important element in the analysis is the careful treatment of a Lichnerowicz-type “no-hair” theorem. From a Frobenius analysis of the asymptotic small-radius behavior, the solution space is found to split into three asymptotic families, one of which contains the classic Schwarzschild solution. These three families are carefully analyzed to determine the corresponding numbers of free parameters in each. One solution family is capable of arising from coupling to a distributional shell of matter near the origin; this family can then match onto an asymptotically flat solution at spatial infinity without encountering a horizon. Another family, with horizons, contains the Schwarzschild solution but includes also non-Schwarzschild black holes. The third family of solutions obtained from the Frobenius analysis is nonsingular and corresponds to “vacuum” solutions. In addition to the three families identified from near-origin behavior, there are solutions that may be identified as “wormholes,” which can match symmetrically onto another sheet of spacetime at finite radius.

The progenitor system(s) and the explosion mechanism(s) of type Ia supernovae (SNe Ia) are still under debate. Nonelectromagnetic observables, in particular, gravitational waves and neutrino emission, of thermoclear supernovae are a complementary window to light curves and spectra for studying these enigmatic objects. A leading model for SNe Ia is the thermonuclear incineration of a near-Chandrasekhar mass carbon-oxygen white dwarf star in a “delayed detonation.” We calculate a three-dimensional hydrodynamic explosion for the N100 delayed-detonation model extensively discussed in the literature, taking the dynamical effects of neutrino emission from all important contributing source terms into account. Although neutrinos carry away $2\times {10}^{49}\mathrm{erg}$ of energy, we confirm the common view that neutrino energy losses are dynamically not very important, resulting in only a modest reduction of final kinetic energy by 2%. We then calculate the gravitational wave signal from the time evolution of the quadrupole moment. Our model radiates $7\times {10}^{39}\mathrm{erg}$ in gravitational waves and the spectrum has a pronounced peak around 0.4 Hz. Depending on viewing angle and polarization, we find that the future space-based gravitational wave missions DECIGO and BBO would be able to detect our source to a distance of $\sim 1.3\mathrm{Mpc}$. We predict a clear signature of the deflagration-to-detonation transition in the neutrino and the gravitational wave signals. If observed, such a feature would be a strong indicator of the realization of delayed detonations in near-Chandrasekhar mass white dwarfs.

We present a code to construct initial data for binary neutron star systems in which the stars are rotating. Our code, based on a formalism developed by Tichy, allows for arbitrary rotation axes of the neutron stars and is able to achieve rotation rates near rotational breakup. We compute the neutron star angular momentum through quasilocal angular momentum integrals. When constructing irrotational binary neutron stars, we find a very small residual dimensionless spin of $\sim 2\times {10}^{-4}$. Evolutions of rotating neutron star binaries show that the magnitude of the stars’ angular momentum is conserved, and that the spin and orbit precession of the stars is well described by post-Newtonian approximation. We demonstrate that orbital eccentricity of the binary neutron stars can be controlled to $\sim 0.1\%$. The neutron stars show quasinormal mode oscillations at an amplitude which increases with the rotation rate of the stars.

We present the redshift-space generalization of the equal-time angular-averaged consistency relations between ($\ell +n$)- and $n$-point polyspectra (i.e., the Fourier counterparts of correlation functions) of the cosmological matter density field. Focusing on the case of the $\ell =1$ large-scale mode and $n$ small-scale modes, we use an approximate symmetry of the gravitational dynamics to derive explicit expressions that hold beyond the perturbative regime, including both the large-scale Kaiser effect and the small-scale fingers-of-god effects. We explicitly check these relations, both perturbatively, for the lowest-order version that applies to the bispectrum, and nonperturbatively, for all orders but for the one-dimensional dynamics. Using a large ensemble of $N$-body simulations, we find that our relation on the bispectrum in the squeezed limit (i.e., the limit where one wave number is much smaller than the other two) is valid to better than 20% up to $1h{\mathrm{Mpc}}^{-1}$, for both the monopole and quadrupole at $z=0.35$, in a $\mathrm{\Lambda }\mathrm{CDM}$ cosmology. Additional simulations done for the Einstein–de Sitter background suggest that these discrepancies mainly come from the breakdown of the approximate symmetry of the gravitational dynamics. For practical applications, we introduce a simple ansatz to estimate the new derivative terms in the relation using only observables. Although the relation holds worse after using this ansatz, we can still recover it within 20% up to $1h{\mathrm{Mpc}}^{-1}$, at $z=0.35$ for the monopole. On larger scales, $k=0.2h{\mathrm{Mpc}}^{-1}$, it still holds within the statistical accuracy of idealized simulations of volume $\sim 8h^{-3}{\mathrm{Gpc}}^3$ without shot-noise error.

In the cold dark matter paradigm, structures form hierarchically, implying that large structures contain smaller substructures. These subhalos will enhance signatures of dark matter annihilation such as gamma rays. In the literature, typical estimates of this boost factor assume a concentration-mass relation for field halos, to calculate the luminosity of subhalos. However, since subhalos accreted in the gravitational potential of their host lose mass through tidal stripping and dynamical friction, they have a quite characteristic density profile, different from that of the field halos of the same mass. In this work, we quantify the effect of tidal stripping on the boost factor, by developing a semianalytic model that combines the mass-accretion history of both the host and subhalos as well as subhalo accretion rates. We find that when subhalo luminosities are treated consistently the boost factor increases by a factor 2–5, compared to the typical calculation assuming a field-halo concentration. This holds for host halos ranging from subgalaxy to cluster masses and is independent of the subhalo mass function or specific concentration-mass relation. The results are particularly relevant for indirect dark matter searches in the extragalactic gamma-ray sky.

We investigate the production of the hypermagnetic gyrotropy when the electric and magnetic gauge couplings evolve at different rates, as it happens in the relativistic theory of the van der Waals forces. If a pseudoscalar interaction breaks the duality symmetry of the corresponding equations, the gyrotropic configurations of the hypermagnetic fields can be amplified from the vacuum during an inflationary stage of expansion. After charting the parameter space of the model in terms of the rates of evolution of the magnetic and electric gauge couplings, we identify the regions where the gyrotropy is sufficiently intense to seed the baryon asymmetry of the Universe at the electroweak epoch while the backreaction constraints, the strong coupling bounds and the other astrophysical limits are concurrently satisfied.

We estimate the momentum diffusion coefficient of a heavy quark within a pure SU(3) plasma at a temperature of about $1.5T_{\mathrm{c}}$. Large-scale Monte Carlo simulations on a series of lattices extending up to ${192}^3\times 48$ permit us to carry out a continuum extrapolation of the so-called color-electric imaginary-time correlator. The extrapolated correlator is analyzed with the help of theoretically motivated models for the corresponding spectral function. Evidence for a nonzero transport coefficient is found and, incorporating systematic uncertainties reflecting model assumptions, we obtain $\kappa =(1.8–3.4)T^3$. This implies that the “drag coefficient,” characterizing the time scale at which heavy quarks adjust to hydrodynamic flow, is ${\eta }_D^{-1}=(1.8–3.4)(T_{\mathrm{c}}/T{)}^2(M/1.5\mathrm{GeV})\mathrm{fm}/\mathrm{c}$, where $M$ is the heavy quark kinetic mass. The results apply to bottom and, with somewhat larger systematic uncertainties, to charm quarks.

A very simple way to obtain comparable baryon and dark matter densities in the early Universe is through their contemporary production from the out-of-equilibrium decay of a mother particle, if both populations are suppressed by comparably small numbers, i.e., the $CP$ violation in the decay and the branching fraction, respectively. We present a detailed study of this kind of scenario in the context of an R-parity violating realization of the minimal supersymmetric standard model in which the baryon asymmetry and the gravitino dark matter are produced by the decay of a Bino. A quantitative determination, in a realistic particle physics framework, of these two quantities is quite involving, due to the non trivial determination of the abundance of the decaying Bino, as well as due to the impact of wash-out processes and of additional sources both for the baryon asymmetry and the DM relic density. To achieve a quantitative determination of the baryon and dark matter abundances, we have implemented and solved a system of coupled Boltzmann equations for the particle species involved in their generation, including all the relevant processes. In the most simple, but still general, limit, in which the processes determining the abundance and the decay rate of the Bino are mediated by degenerate right-handed squarks, the correct values of the dark matter and baryon relic densities are achieved for a Bino mass between 50 and 100 TeV, Gluino next-to-lightest supersymmetric particle mass in the range 15–60 TeV, and a gravitino mass between 100 GeV and few TeV. These high masses are unfortunately beyond the kinematical reach of the LHC. On the contrary, an antiproton signal from the decays of the gravitino lightest supersymmetric particle might be within the sensibility of AMS-02 and gamma-ray telescopes.

The candidate of minimal dark matter (MDM) is limited if one demands perturbativity up to a very high scale, and it was believed that the MDM model with a real scalar septuplet could keep perturbative up to the Planck or grand unified theory scale. In this work we point out that it is not true after taking into account the running of the quartic self-couplings of the scalar septuplet. For the septuplet mass around 10 TeV, which is suggested by the observed dark matter relic abundance, these couplings would hit the Landau pole at a scale $\sim {10}^8–{10}^9\mathrm{GeV}$, much lower than the Planck scale. We attempt to push up the Landau pole scale as high as possible by proposing an extension with extra Yukawa interactions of the septuplet. We find that in principle the Landau pole could be deferred to a scale of $\sim {10}^{14}\mathrm{GeV}$ if one could tolerate a serious fine-tuning of the initial condition of the Yukawa coupling. Moreover, if the MDM particle mass could be relaxed to $\sim {10}^8\mathrm{GeV}$, which would need some nonthermal production mechanisms to give a correct relic abundance, the Landau pole scale could be pushed up above the Planck scale.

Lattice QCD with background magnetic fields is used to calculate the magnetic moments and magnetic polarizabilities of the nucleons and of light nuclei with $A\le 4$, along with the cross section for the $M1$ transition $np\to d\gamma$, at the flavor SU(3)-symmetric point where the pion mass is $m_{\pi }\sim 806\mathrm{MeV}$. These magnetic properties are extracted from nucleon and nuclear energies in six uniform magnetic fields of varying strengths. The magnetic moments are presented in a recent article [S. Beane et al., Phys. Rev. Lett. 113, 252001 (2014)]. For the charged states, the extraction of the polarizability requires careful treatment of Landau levels, which enter nontrivially in the method that is employed. The nucleon polarizabilities are found to be of similar magnitude to their physical values, with ${\beta }_p=5.22(\genfrac{}{}{0ex}{}{+0.66}{-0.45})(0.23)\times {10}^{-4}{\mathrm{fm}}^3$ and ${\beta }_n=1.253(\genfrac{}{}{0ex}{}{+0.056}{-0.067})(0.055)\times {10}^{-4}{\mathrm{fm}}^3$, exhibiting a significant isovector component. The dineutron is bound at these heavy quark masses, and its magnetic polarizability, ${\beta }_{nn}=1.872(\genfrac{}{}{0ex}{}{+0.121}{-0.113})(0.082)\times {10}^{-4}{\mathrm{fm}}^3$, differs significantly from twice that of the neutron. A linear combination of deuteron scalar and tensor polarizabilities is determined by the energies of the $j_z=\pm 1$ deuteron states and is found to be ${\beta }_{d,\pm 1}=4.4(\genfrac{}{}{0ex}{}{+1.6}{-1.5})(0.2)\times {10}^{-4}{\mathrm{fm}}^3$. The magnetic polarizabilities of the three-nucleon and four-nucleon systems are found to be positive and similar in size to those of the proton, ${\beta }_{{}^3\mathrm{He}}=5.4(\genfrac{}{}{0ex}{}{+2.2}{-2.1})(0.2)\times {10}^{-4}{\mathrm{fm}}^3$, ${\beta }_{{}^{3}H}=2.6(1.7)(0.1)\times {10}^{-4}{\mathrm{fm}}^3$, and ${\beta }_{{}^4\mathrm{He}}=3.4(\genfrac{}{}{0ex}{}{+2.0}{-1.9})(0.2)\times {10}^{-4}{\mathrm{fm}}^3$. Mixing between the $j_z=0$ deuteron state and the spin-singlet $np$ state induced by the background magnetic field is used to extract the short-distance two-nucleon counterterm, ${\overline{L}}_1$, of the pionless effective theory for $NN$ systems (equivalent to the meson-exchange current contribution in nuclear potential models) that dictates the cross section for the $np\to d\gamma$ process near threshold. Combined with previous determinations of $NN$ scattering parameters, this enables an ab initio determination of the threshold cross section at these unphysical masses.

The dilepton production rate from the deconfined medium is analyzed with the photon self-energies constructed from quark propagators obtained by lattice numerical simulation for two values of temperature, $T=1.5T_{\mathrm{c}}$ and $3T_{\mathrm{c}}$, above the critical temperature $T_{\mathrm{c}}$. The photon self-energy is calculated by the Schwinger-Dyson equation with the lattice quark propagtor and a vertex function determined so as to satisfy the Ward-Takahashi identity. The obtained dilepton production rate at zero momentum exhibits divergences reflecting van Hove singularity and is significantly enhanced around $\omega \simeq T$ compared with the rate obtained by the perturbative analysis.

The energy spectrum of high-energy neutrinos reported by the IceCube Collaboration shows a dip between 400 TeV and 1 PeV. One intriguing explanation is that high-energy neutrinos scatter with the cosmic neutrino background through an $\sim \mathrm{MeV}$ mediator. Taking the density matrix approach, we develop a formalism to study the propagation of PeV neutrinos in the presence of the new neutrino interaction. If the interaction is flavored such as the gauged $L_{\mu }-L_{\tau }$ model we consider, the resonant collision may not suppress the PeV neutrino flux completely. The new force mediator may also contribute to the number of effectively massless degrees of freedom in the early Universe and change the diffusion time of neutrinos from the supernova core. Astrophysical observations such as big bang nucleosynthesis and supernova cooling provide an interesting test for the explanation.