The ordering of the neutrino mass eigenstates is one of the fundamental open questions in neutrino physics. While current-generation neutrino oscillation experiments are able to produce moderate indications on this ordering, upcoming experiments of the next generation aim to provide conclusive evidence. In this paper we study the combined performance of the two future multi-purpose neutrino oscillation experiments JUNO and the IceCube Upgrade, which employ two very distinct and complementary routes toward the neutrino mass ordering. The approach pursued by the 20 kt medium-baseline reactor neutrino experiment JUNO consists of a careful investigation of the energy spectrum of oscillated ${\overline{\nu }}_e$ produced by ten nuclear reactor cores. The IceCube Upgrade, on the other hand, which consists of seven additional densely instrumented strings deployed in the center of IceCube DeepCore, will observe large numbers of atmospheric neutrinos that have undergone oscillations affected by Earth matter. In a joint fit with both approaches, tension occurs between their preferred mass-squared differences $\mathrm{\Delta }{m}_{31}^2=m_3^2-m_1^2$ within the wrong mass ordering. In the case of JUNO and the IceCube Upgrade, this allows to exclude the wrong ordering at $>5\sigma$ on a timescale of 3–7 years—even under circumstances that are unfavorable to the experiments’ individual sensitivities. For PINGU, a 26-string detector array designed as a potential low-energy extension to IceCube, the inverted ordering could be excluded within 1.5 years (3 years for the normal ordering) in a joint analysis.

We construct both local states and scattering states with finite energy in global AdS by inserting properly regularized operators in the CFT of arbitrary conformal dimension ($\mathrm{\Delta }$) at an instant of time. We give the state fixed angular momentum $(\ell )$ by integrating the result over a sphere with appropriate spherical harmonics. The energy of the states and their angular resolution are computed with CFT operator methods and are independent of having an AdS interpretation. In the semiclassical limit of large conformal dimension operators, these correspond to single particles localized within sub-AdS scales with width $1/\sqrt{\mathrm{\Delta }}$ in AdS units, whose subsequent evolution is controlled by bulk geodesics. Our construction allows us to place a particle in any desired geodesic. For radial geodesics, we show that the amplitude to produce the desired state can be thought of as a regularized tunneling amplitude from the boundary to the radial turning point of the radial geodesic, while for other geodesics we argue that the insertion is at the outermost radial turning point of the corresponding geodesic.

We study integrability on the supergravity vacuum dual to the field-theoretical $\mathrm{\Omega }$ deformation of $\mathcal{N}=4$ super Yang-Mills theory. The deformation manifests itself as turning on a Kalb-Ramond field on the (Euclidean) ${\mathrm{AdS}}_5\times {\mathrm{S}}^5$, while the associated $H_3$ flux ignores half of the geometric isometries. By constructing appropriate string embeddings that incorporate the essential $H_3$ flux contribution on this background, we study their fluctuations through the associated Hamiltonian systems. Each and every case demonstrates that the string exhibits nonintegrable dynamics, which in turn suggests that the $\mathrm{\Omega }$ deformation does not preserve classical integrability.

We discuss the (non)existence of superregular scalar clouds (i.e., bound states of a massive and complex-valued scalar field $\mathrm{\Psi }$) around exact extremal ($a=M$) Kerr black holes (BHs) possessing bounded radial derivatives at the horizon (in Boyer-Lindquist coordinates) as opposed to similar cloud solutions that exist but with unbounded derivatives in the same coordinate system. The latter solutions have been reported recently both analytically and numerically. The superregular clouds cannot be obtained from the regular clouds around subextremal Kerr BHs ($|a|<M$) in the limit of extremality ($a\to M$), as in this limit the radial derivatives of $\mathrm{\Psi }$ at the horizon $r_H$ diverge when $r_H\to r_H^{\mathrm{ext}}≔M=a$; thus, such superregular clouds must be analyzed separately. We conclude that the superregular clouds, which are found in the exact extremal scenario ($a=M$), are not continuously connected with the regular ones in the limit of extremality ($a\to M$). Remarkably, the spectrum leading to the existence of the radial part of the full solution of these superregular clouds (which obeys a Teukolsky equation) is given by the exact formula $M=a=\frac{1}{2\mu }\sqrt{m^2+{[-\kappa +\sqrt{{\kappa }^2+m^2}]}^2}$, which depends on three (positive) integers: the principal number $n$, the magnetic number $m$, and an integer $j$, related to the type of regularity at the horizon. Here, $\kappa =j+n$, and $\mu$ is the mass associated with $\mathrm{\Psi }$. This spectrum depends implicitly on the orbital number $l$, an integer number that determines the existence of well-behaved spheroidal harmonics which are associated with the angular part of the cloud solution. Since the separation constants that are obtained from the superregularity conditions in the radial part of the solution do not coincide, in general, with the standard separation constants required for the spheroidal harmonics to be well behaved on the axis of symmetry, we conclude that nontrivial boson clouds having such superregularity conditions cannot exist in the background of an exact extremal Kerr BH. The only exception to this conclusion is in the limit $n\to \infty$ and $m\ll n$. In such a large-$n$ limit, consistency in the separation constants leads to a quadratic Diophantine equation of Pell’s type for the integer numbers $(l,m)$. Such a Pell’s equation can be readily solved using the standard techniques. In that instance, well-behaved spheroidal harmonics are obtained, and thus, well-behaved nontrivial superregular clouds can be computed. Of course, this situation does not preclude the existence of other kinds of smooth cloud solutions for any other $n$, not necessarily large (e.g., clouds with a noninteger $\kappa$) when using a better-behaved coordinate system at the horizon (e.g., Wheeler’s tortoise coordinate or proper radial distance).

The post-Minkowskian approach to gravitationally interacting binary systems (i.e., perturbation theory in $G$, without assuming small velocities) is extended to the computation of the dynamical effects induced by the tidal deformations of two extended bodies, such as neutron stars. Our derivation applies general properties of perturbed actions to the effective field theory description of tidally interacting bodies. We compute several tidal invariants (notably the integrated quadrupolar and octupolar actions) at the first post-Minkowskian order. The corresponding contributions to the scattering angle are derived.

In this work we derived a rotating and nonlinear magnetic-charged black hole surrounded by quintessence using the Newman-Janis algorithm. Considering the state parameter ${\omega }_q=-3/2$, we studied the event horizons, the ergosphere, and the zero angular momentum observer. We found that the existence of the outer horizon is constrained by the values of the charge $Q$. Furthermore, we found that the ergoregion increases when both the charge $Q$ and the spin parameter $a$ are increased. On the other hand, regarding equatorial circular orbits, we studied the limit given by the static radius on the existence of circular geodesics, the photon circular geodesics, and the innermost stable circular orbits. We show that photon circular orbits do not depend strongly on $Q$, and $r_{\mathrm{ISCO}}$ is constrained by the values of charge.

The tests of parity symmetry in the gravitational interaction is an attractive issue in gravitational-wave astronomy. In the general theories of gravity with parity violation, one of the fundamental results is that primordial gravitational waves (PGWs) produced during slow-roll inflation is circularly polarized. In this article, we investigate the polarization of PGWs in the recently proposed ghost-free parity-violating gravity, which generalizes Chern-Simons gravity by including higher derivatives of the coupling scalar field. For this purpose, we first construct the approximate analytical solution to the mode function of the PGWs during slow-roll inflation by using the uniform asymptotic approximation. With the approximate solution, we explicitly calculate the power spectrum and the corresponding circular polarization of the PGWs analytically, and find that the contributions of the higher derivatives of the coupling scalar field to the circular polarization are of the same order of magnitude as that of Chern-Simons gravity. The degree of circular polarization of PGWs is suppressed by the energy scale of parity violation in gravity, which is unlikely to be detected using only the two-point statistics of future cosmic microwave background data.

Fermi-LAT observations have strongly constrained dark matter annihilation through the joint-likelihood analysis of dwarf spheroidal galaxies (dSphs). These constraints are expected to be robust because dSphs have measurable dark matter content and produce negligible astrophysical emission. However, each dSph is dim, with a predicted flux that typically falls below the accuracy of the background model. We show that this significantly diminishes the reliability of previous joint-likelihood algorithms, and we develop an improved analysis that directly accounts for the effect of background mismodeling. This method produces more robust limits and detections of dark matter in both real and mock data. We calculate improved limits on the dark matter annihilation cross section, which differ by nearly a factor of 2 from previous analyses—despite examining identical data.

A dense neutrino gas, such as the one anticipated in the supernova environment, can experience fast neutrino flavor conversions on scales much shorter than those expected in vacuum probably provided that the angular distributions of ${\nu }_e$ and ${\overline{\nu }}_e$ cross each other. We perform a detailed investigation of the neutrino angular distributions obtained by solving the Boltzmann equations for fixed matter profiles of some representative snapshots during the postbounce phase of core-collapse supernovae in multidimensional calculations of a $11.2{\mathrm{M}}_{\odot }$ and a $27{\mathrm{M}}_{\odot }$ progenitor model. Although the $11.2{\mathrm{M}}_{\odot }$ model features ${\nu }_e-{\overline{\nu }}_e$ angular crossings and the associated fast modes at different time snapshots, the $27{\mathrm{M}}_{\odot }$ model does not show any crossings within the decoupling region. We show that this can be understood by studying the multipole components of the neutrino distributions. In fact, there is a higher chance for the occurrence of ${\nu }_e-{\overline{\nu }}_e$ angular crossings for the zones where the multipole components of the neutrino distributions are strong enough. We also show that there can exist more than one crossing between the angular distributions of ${\nu }_e$ and ${\overline{\nu }}_e$. In addition, apart from the crossings within the neutrino decoupling region, there is a class of ${\nu }_e-{\overline{\nu }}_e$ angular crossings that appears very deep inside the protoneutron star.

We consider hadronic weak decays of beauty baryons into charmless baryons and pseudoscalar mesons in a general framework based on $SU(3)$ decomposition of the decay amplitudes. The advantage of this approach lies in the ability to perform an $SU(3)$ analysis of these decays without any particular set of dynamical assumptions while accounting for the effects of an arbitrarily broken $SU(3)$ flavor symmetry. Dictated by the symmetries of the effective Hamiltonian that allow us to relate or neglect reduced $SU(3)$ amplitudes, we derive several sum rule relations between amplitudes and relations between $CP$ asymmetries in these decays and identify those that hold even if $SU(3)$ is broken.

We define the “entropy of ignorance” which quantifies the entropy associated with ability to perform only a partial set of measurement on a quantum system. For the parton model the entropy of ignorance is equal to the Boltzmann entropy of a classical system of partons. We analyze a calculable model used for describing low x gluons in Color Glass Condensate approach, which has similarities with the parton model of QCD. In this model we calculate the entropy of ignorance in the particle number basis as well as the entanglement entropy of the observable degrees of freedom. We find that the two are similar at high momenta, but differ by a factor of order unity at low momenta. This holds for the Renyi as well as von Neumann entropies. We conclude that the entanglement does not seem to play an important role in the context of the parton model.

We studied a simple model of the hidden sector that consists of a Dirac fermion $\chi$ and a spontaneously broken $U(1{)}_s$ symmetry. The dark sector is connected to the Standard Model (SM) via three right-handed SM singlet neutrinos, $N_R$’s, and the kinetic mixing between $U(1{)}_s$ and $U(1{)}_Y$. A mixing between the scalar $\varphi$ that breaks $U(1{)}_s$ and the SM Higgs boson $H$ is implemented via the term ${\varphi }^{†}\varphi H^{†}H$, and this provides a third connection to the SM. Integrating out the $N_R$ at a high scale not only gives the active neutrinos $\nu$ masses but generates effective Dirac-type couplings between $\nu$ and $\chi$. This changes the usual type-I seesaw mechanism results for active neutrino masses and makes $\chi$ behave like a sterile neutrino even though its origin is in the hidden sector. Note that $\chi$ is also split into a pair of Majorana fermions. The amount of splitting depends on the parameters. If the lighter of the pair has a mass around keV, its lifetime is longer than the age of the Universe and it can be a warm dark matter candidate. Signatures of $\chi$ in high precision Kurie plots of nuclei $\beta$ decays and low energy neutrino nuclei coherent scatterings are discussed. The model also induces new invisible $Z$ decay modes that can be searched for in future Z factories.

We investigate the parton distribution functions (PDFs) of the pion and the kaon by combining quantum chromodynamics (QCD) evolution with the basis light front quantization. The initial PDFs result from the light front wave functions obtained by diagonalizing the effective Hamiltonian consisting of the holographic QCD confinement potential, a complementary longitudinal confinement potential, and the color-singlet Nambu–Jona-Lasinio interactions. The valence-quark PDF of the pion, after QCD evolution, is consistent with the result from the E-0615 experiment at Fermilab. Meanwhile, the pion structure function calculated from the PDFs agrees with the ZEUS and the H1 experiments at DESY-HERA for large $x$. Additionally, the ratio of the up quark PDF of the kaon to that of the pion is in agreement with the NA-003 experiment at CERN. We also present the cross section for the pion-nucleus induced Drell-Yan process with the obtained pion PDFs supplemented by the PDFs of the target nuclei.

A four-body amplitude analysis of the $B^{-}\to D^{*+}{\pi }^{-}{\pi }^{-}$ decay is performed, where fractions and relative phases of the various resonances contributing to the decay are measured. Several quasi-model-independent analyses are performed aimed at searching for the presence of new states and establishing the quantum numbers of previously observed charmed meson resonances. In particular the resonance parameters and quantum numbers are determined for the $D_1(2420)$, $D_1(2430)$, $D_0(2550)$, $D_1^{*}(2600)$, $D_2(2740)$ and $D_3^{*}(2750)$ states. The mixing between the $D_1(2420)$ and $D_1(2430)$ resonances is studied and the mixing parameters are measured. The dataset corresponds to an integrated luminosity of $4.7{\mathrm{fb}}^{-1}$, collected in proton-proton collisions at center-of-mass energies of 7, 8 and 13 TeV with the LHCb detector.

During an accelerated expansion of the Universe, quantum fluctuations of sub-Planckian size can be stretched outside the horizon and be regarded effectively classical. Recently, it has been conjectured that such horizon-crossing of trans-Planckian modes never happens inside theories of quantum gravity (the trans-Planckian censorship conjecture, TCC). We point out several conceptual problems of this conjecture, which is in itself formulated as a statement on the restriction of possible scenarios in a theory: by contrast a standard swampland conjecture is a restriction of possible theories in the landscape of the quantum gravity. We emphasize the concept of swampland universality, i.e., that a swampland conjecture constrains any possible scenario in a given effective field theory. In order to illustrate the problems clearly we introduce several versions of the conjecture, where the TCC condition is imposed differently to scenarios realizable in a given theory. We point out that these different versions of the conjecture lead to observable differences: a TCC violation in another Universe can exclude a theory, and such reduction of the landscape restricts possible predictions in our Universe. Our analysis raises the question of whether or not the trans-Planckian censorship conjecture can be regarded as a swampland conjecture concerning the existence of UV completion.

Attempts to resolve the long-standing Fermion mass hierarchy problem in frames of the $\mathrm{AdS}/\mathrm{CFT}$ correspondence demand the knowledge of bulk fermion masses. The approach of the “old” conformal bootstrap in the anti-de Sitter (AdS) context permitted calculating bulk masses of scalar fields, as it was shown in three previous papers B. L. Altshuler [arXiv:1810.01105; Int. J. Mod. Phys. 2050001 (2020); J. High Energy Phys. 01 (2020) 137]. In the present paper, this approach is extended to physically more interesting spin-$1/2$ bulk fields. Calculation of spinor-scalar vertices is performed in physical AdS space, and unexpectedly simple expressions for spinor-scalar bubbles (two-point one-loop self-energy Witten diagrams) are obtained. The “double-trace from UV to IR flow” subtraction of UV divergences used earlier in calculations of the UV-finite bulk tadpoles is applied to bubbles. This permitted us to write down in the frame of the old conformal bootstrap approach the nontrivial spectral equations for the bulk fermion masses; the SU(N) Yukawa model of spinor fields interacting with conformal invariant scalar field in case of four boundary dimensions is considered as a specific example.

In this paper, we successfully derive the Bekenstein-Hawking entropy for Schwarzschild black holes in various dimensions by using a nontrivial phase space. It is appealing to notice that the thermodynamics of a Schwarzschild black hole actually behaves like that of a 1-dimensional quantum mechanical system. Our result suggests that black hole should be viewed as a system with the equation of state $P=\rho$, and it also suggests that a holographic stage should exist in the early universe.

The carriers in graphene tuned close to the Dirac point envisage signatures of the strongly interacting fluid and are subject to hydrodynamic description. The important question is whether strong disorder induces the metal-insulator transition in this two-dimensional material. The bound on the conductivity tensor found earlier within the single current description implies that the system does not feature metal-insulator transition. The linear spectrum of the graphene imposes the phase-space constraints and calls for the two-current description of interacting electron and hole liquids. Based on the gauge/gravity correspondence, using the linear response of the black brane with broken translation symmetry in Einstein-Maxwell gravity with the auxiliary $U(1)$-gauge field, responsible for the second current, we have calculated the lower bound of the DC conductivity in the holographic model of graphene. The calculations show that the bound on the conductivity depends on the coupling between both $U(1)$ fields and for a physically justified range of parameters it departs only weakly from the value found for a model with the single $U(1)$ field.

We study M-theory compactification on ${\mathbb{T}}^7/{\mathbb{Z}}_2^3$ in the presence of a seven-flux, metric fluxes, and KK monopoles. The effective four-dimensional supergravity has seven chiral multiplets whose couplings are specified by the $G_2$-structure of the internal manifold. We supplement the corresponding superpotential by a KKLT type nonperturbative exponential contribution for all, or for some of the seven moduli, and find a discrete set of supersymmetric Minkowski minima. We also study type IIA and type IIB string theory compactified on ${\mathbb{T}}^6/{\mathbb{Z}}_2^2$. In type IIA, we use a six-flux, geometric fluxes, and nonperturbative exponents. In type IIB theory, we use F and H fluxes, and nongeometric Q and P fluxes, corresponding to consistently gauged supergravity with certain embedding tensor components, without nonperturbative exponents. Also in these situations, we produce discrete Minkowski minima. Finally, to construct dS vacua starting from these Minkowski progenitors, we follow the procedure of mass production of dS vacua.