The possibility that dark matter, whose existence is inferred from the study of galactic rotation curves, and from the mass deficit in galaxy clusters, can be in the form of a Bose-Einstein condensate has been extensively investigated lately. In the present work, we consider a detailed analysis of the astrophysical properties of the Bose-Einstein condensate dark matter halos that could provide clear observational signatures that help discriminate between different dark matter models. In the Bose-Einstein condensation model, dark matter can be described as a nonrelativistic, gravitationally confined Newtonian gas, whose density and pressure are related by a polytropic equation of state with index $n=1$. The mass and gravitational properties of the condensate halos are obtained in a systematic form, including the mean logarithmic slopes of the density and of the tangential velocity. The lensing properties of the condensate dark matter are investigated in detail. In particular, a general analytical formula for the surface density, an important quantity that defines the lensing properties of a dark matter halos, is obtained in the form of series expansions. This enables arbitrary-precision calculations of the surface mass density, deflection angle, deflection potential, and of the magnification factor, thus giving the possibility of the comparison of the predicted lensing properties of the condensate dark matter halos with observations. The stability properties of the condensate halos are also investigated by using the scalar and the tensor virial theorems, respectively, and the virial perturbation equation for condensate dark matter halos is derived. As an application of the scalar virial theorem, we consider the problem of the stability of a slowly rotating and slightly disturbed galactic dark matter halo. For such a halo, the oscillation frequencies and the stability conditions are obtained in the linear approximation.

In nonlinear electrodynamics, QED included, we find a static solution to the field equations with an electric charge as its source, which is comprised of homogeneous parallel magnetic and electric fields, and a radial spherically nonsymmetric long-range magnetic field, whose magnetic charge is proportional to the electric charge and also depends on the homogeneous component of the solution.

We study supersymmetry constraints on higher derivative deformations of type IIB supergravity by consideration of superamplitudes. Combining constraints of on-shell supervertices and basic results from string perturbation theory, we give a simple argument for the nonrenormalization theorem of Green and Sethi, and some of its generalizations.

The effect of a strong magnetic field on the location of the critical end point (CEP) in the QCD phase diagram is discussed under different scenarios. In particular, we consider the contribution of the vector interaction and take into account the inverse magnetic catalysis obtained in lattice QCD calculations at zero chemical potential. The discussion is realized within the ($2+1$) Polyakov–Nambu–Jona-Lasinio model. It is shown that the vector interaction and the magnetic field have opposite competing effects, and that the winning effect depends strongly on the intensity of the magnetic field. The inverse magnetic catalysis at zero chemical potential has two distinct effects for magnetic fields above $\gtrsim 0.3{\mathrm{GeV}}^2$: it shifts the CEP to lower chemical potentials, hinders the increase of the CEP temperature and prevents a too large increase of the baryonic density at the CEP. For fields $eB<0.1{\mathrm{GeV}}^2$ the competing effects between the vector contribution and the magnetic field can move the CEP to regions of temperature and density in the phase diagram that could be more easily accessible to experiments.

We study some implications of the presence of two new scalar weak doublets beyond the standard model which have zero vacuum expectation values and are charged under an extra Abelian gauge symmetry. The additional gauge sector does not couple directly to standard-model particles. We investigate specifically the effects of the scalars on oblique electroweak parameters and on the interactions of the 125 GeV Higgs boson, especially its decay modes $h\to \gamma \gamma ,\gamma Z$ and trilinear self-coupling, all of which will be probed with improved precision in future Higgs measurements. Moreover, we explore how the new scalars may give rise to strongly first-order electroweak phase transition and also show its correlation with sizable modifications to the Higgs trilinear self-coupling.

Partial-wave operators for lattice QCD are developed in order to facilitate the identification of the spins of two-hadron scattering states corresponding to zero total momentum. Taking the periodic boundary conditions for lattice states into account, orthogonal sets of partial-wave operators for orbital angular momentum are identified. When combined with the intrinsic spins of the hadrons, orthogonal sets of parent operators for total angular momentum $J$ and projection $M$ are obtained. The parent operators are subduced to irreducible representations of the octahedral group in order to obtain descendant operators for use in lattice calculations. The descendant operators retain orthogonality with respect to $J$. The spin of a state can be identified by the spin of parent operators that dominate creation of the state. For nonzero total momentum, operators are developed for a range of helicities and they are subduced to irreducible representations corresponding to the different directions of total momentum. Sets of operators that include a sufficient range of helicities allow identification of spin $J$ when a state couples to operators with helicities less than or equal to $J$, but not to operators with higher helicities.

We report on a theoretical study of the ${\pi }^{-}p\to D^{-}{D}^{0}p$ reaction near threshold within an effective Lagrangian approach. The production process is described by $t$-channel $D^{*0}$ meson exchange, $s$-channel nucleon pole, and $u$-channel ${\mathrm{\Sigma }}_c^{++}$ exchange. In our work, the final $D^{0}p$ results from the ground ${\mathrm{\Lambda }}_c^{+}(2286)$ state and also dominantly from the excited ${\mathrm{\Lambda }}_c^{+}(2940)$ state which is assumed as a $D^{*0}p$ molecular state with spin parity $J^P={\frac{1}{2}}^{+}$ or ${\frac{1}{2}}^{-}$. We calculate the total cross section of the ${\pi }^{-}p\to D^{-}{D}^{0}p$ reaction. It is shown that the spin-parity assignment of ${\frac{1}{2}}^{-}$ for ${\mathrm{\Lambda }}_c^{+}(2940)$ gives a sizable enhancement for the total cross section in comparison with a choice of $J^p={\frac{1}{2}}^{+}$. However, our theoretical result of the total cross section is sensitive to the value of the cutoff parameter involved in the form factor of the exchanged off-shell particles. Moreover, we also calculate the second order differential cross section and find it can be used to determine the parity of the ${\mathrm{\Lambda }}_c^{+}(2940)$. It is expected that our model calculations can be tested by future experiments at J-PARC in Japan.

We introduce four different types of data-driven analyses with different levels of robustness that constrain the size of the Higgs–charm Yukawa coupling: (i) Recasting the vector-boson associated $Vh$ analyses that search for the bottom-pair final state. We use this mode to directly and model independently constrain the Higgs-to-charm coupling, $y_c/y_c^{\mathrm{SM}}\lesssim 234$. (ii) The direct measurement of the total width, $y_c/y_c^{\mathrm{SM}}\lesssim 120–140$. (iii) The search for $h\to J/\psi \gamma$, $y_c/y_c^{\mathrm{SM}}\lesssim 220$. (iv) A global fit to the Higgs signal strengths, $y_c/y_c^{\mathrm{SM}}\lesssim 6.2$. A comparison with $t\overline{t}h$ data allows us to show that the Higgs does not couple to quarks in a universal way, as is expected in the Standard Model. Finally, we demonstrate how the experimental collaborations can further improve our direct bound by roughly an order of magnitude by charm tagging, as is already used in new-physics searches.

We explore the effect of the electrodynamics $\theta$ angle on the macroscopic properties of black hole horizons. Using only classical Einstein-Maxwell-Chern-Simons theory in ($3+1$) dimensions, in the form of the membrane paradigm, we show that in the presence of the $\theta$ term, a black hole horizon behaves as a Hall conductor, for an observer hovering outside. We study how localized perturbations created on the stretched horizon scramble on the horizon by dropping a charged particle. We show that the $\theta$ angle affects the way perturbations scramble on the horizon, in particular, it introduces vortices without changing the scrambling time. This Hall scrambling of information is also expected to occur on cosmological horizons.

We investigate the properties of the Dirac operator on manifolds with boundaries in the presence of the Atiyah-Patodi-Singer boundary condition. An exact counting of the number of edge states for boundaries with isometry of a sphere is given. We show that the problem with the above boundary condition can be mapped to one where the manifold is extended beyond the boundary and the boundary condition is replaced by a delta function potential of suitable strength. We also briefly highlight how the problem of the self-adjointness of the operators in the presence of moving boundaries can be simplified by suitable transformations which render the boundary fixed and modify the Hamiltonian and the boundary condition to reflect the effect of moving boundary.

In this paper we investigate the chameleon effect in the different conformal frames of the Brans-Dicke (BD) theory. Given that, in the standard literature on the subject, the chameleon is described in the Einstein frame almost exclusively, here we pay special attention to the description of this effect in the Jordan and in the string frames. It is shown that, in general, terrestrial and solar system bounds on the mass of the BD scalar field, and bounds of cosmological origin, are difficult to reconcile at once through a single chameleon potential. We point out that, in a cosmological context, provided that the effective chameleon potential has a minimum within a region of constant density of matter, the Brans-Dicke theory transmutes into general relativity with a cosmological constant, in that region. This result, however, can be only locally valid.

We study the stability of a spherically symmetric perturbation around the flat Friedmann–Lemaître–Robertson–Walker spacetime in the ghost-free bigravity theory, retaining nonlinearities of the helicity-0 mode of the massive graviton. It has been known that, when the graviton mass is smaller than the Hubble parameter, homogeneous and isotropic spacetimes suffer from the Higuchi-type ghost or the gradient instability against the linear perturbation in the bigravity. Hence, the bigravity theory has no healthy massless limit for cosmological solutions at linear level. In this paper we show that the instabilities can be resolved by taking into account nonlinear effects of the scalar graviton mode for an appropriate parameter space of coupling constants. The growth history in the bigravity can be restored to the result in general relativity in the early stage of the Universe, in which the Stückelberg fields are nonlinear and there is neither ghost nor gradient instability. Therefore, the bigravity theory has the healthy massless limit, and cosmology based on it is viable even when the graviton mass is smaller than the Hubble parameter.

Numerical simulations of Blandford-Znajek energy extraction at high spin have revealed that field lines tend to bunch near the poles of the event horizon. We show that this behavior can be derived analytically from the assumption of fixed functional dependence of current and field line rotation on magnetic flux. The argument relies crucially on the existence of the Znajek condition, which offers nontrivial information about the fields on the horizon without requiring a full force-free solution. We also provide some new analytic expressions for the parabolic field configuration.

The Planck value of the spectral index can be interpreted as $n_s=1-2/N$ in terms of the number of $e$-foldings $N$. An appealing explanation for this phenomenological observation is provided by $\alpha$-attractors: the inflationary predictions of these supergravity models are fully determined by the curvature of the Kähler manifold. We provide a novel formulation of $\alpha$-attractors which only involves a single chiral superfield. Our construction involves a natural deformation of no-scale models and employs these to construct a de Sitter plateau with an exponential falloff. Finally, we show how analogous structures with a flat Kähler geometry arise as a singular limit of such $\alpha$-scale models.

When the gauge fields have derivative couplings to scalars, like in the case of the relativistic theory of Van der Waals (or Casimir-Polder) interactions, conformal invariance is broken but the magnetic and electric susceptibilities are not bound to coincide. We analyze the formation of large-scale magnetic fields in slow-roll inflation and find that they are generated at the level of a few hundredths of a nG and over typical length scales between few Mpc and 100 Mpc. Using a new time parametrization that reduces to conformal time but only for coincident susceptibilities, the gauge action is quantized while the evolution equations of the corresponding mode functions are more easily solvable. The power spectra depend on the normalized rates of variation of the two susceptibilities (or of the corresponding gauge couplings) and on the absolute value of their ratio at the beginning of inflation. We pin down explicit regions in the parameter space where all the physical requirements (i.e., the backreaction constraints, the magnetogenesis bounds and the naturalness of the initial conditions of the scenario) are jointly satisfied. Weakly coupled initial data are favored if the gauge couplings are of the same order at the end of inflation. Duality is systematically used to simplify the analysis of the wide parameter space of the model.

Temperature dependence of the $U_A(1)$ anomaly is investigated by taking into account mesonic fluctuations in the $U(3)\times U(3)$ linear sigma model. A field dependent anomaly coefficient function of the effective potential is calculated within the finite temperature functional renormalization group approach. The applied approximation scheme is a generalization of the chiral invariant expansion technique developed in [G. Fejős, Phys. Rev. D 90, 096011 (2014).]. We provide an analytic expression and also numerical evidence that depending on the relationship between the two quartic couplings, mesonic fluctuations can either strengthen or weaken the anomaly as a function of the temperature. The role of the six-point invariant of the $U(3)\times U(3)$ group, and therefore the stability of the chiral expansion is also discussed in detail.

We demonstrate the suitability of tensor network techniques for describing the thermal evolution of lattice gauge theories. As a benchmark case, we have studied the temperature dependence of the chiral condensate in the Schwinger model, using matrix product operators to approximate the thermal equilibrium states for finite system sizes with nonzero lattice spacings. We show how these techniques allow for reliable extrapolations in bond dimension, step width, system size and lattice spacing, and for a systematic estimation and control of all error sources involved in the calculation. The reached values of the lattice spacing are small enough to capture the most challenging region of high temperatures and the final results are consistent with the analytical prediction by Sachs and Wipf over a broad temperature range.

The new data reported by ALICE on the production of light nuclei with $p_{\perp }\lesssim 10\mathrm{GeV}$ in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\mathrm{TeV}$ are used to compute an order-of-magnitude estimate of the expected production cross sections of light nuclei in proton-proton collisions at high transverse momenta. We compare the hypertriton, helium-3, and deuteron production cross sections to that of $X(3872)$, measured in prompt $pp$ collisions by CMS. The results we find suggest a different production mechanism for the $X(3872)$, making questionable any loosely bound molecule interpretation.