We propose the RES-NOVA project, which will hunt neutrinos from core-collapse supernovae (SN) via coherent elastic neutrino-nucleus scattering ($\mathrm{CE}\nu \mathrm{NS}$) using an array of archaeological lead (Pb) based cryogenic detectors. The high $\mathrm{CE}\nu \mathrm{NS}$ cross section on Pb and the ultrahigh radiopurity of archaeological Pb enable the operation of a high statistics experiment equally sensitive to all neutrino flavors with reduced detector dimensions in comparison with existing neutrino observatories and easy scalability to larger detector volumes. RES-NOVA is planned to operate according to three phases with increasing detector volumes: $(60\mathrm{cm}{)}^3$, $(140\mathrm{cm}{)}^3$, and ultimately $15\times (140\mathrm{cm}{)}^3$. It will be sensitive to SN bursts up to Andromeda with $5\sigma$ sensitivity with already existing technologies and will have excellent energy resolution with a 1 keV threshold. Within our Galaxy, it will be possible to discriminate core-collapse SN from black-hole-forming collapses with no ambiguity even in the first phase of RES-NOVA. The average neutrino energy of all flavors, the SN neutrino light curve, and the total energy emitted in neutrinos can potentially be constrained with a precision of a few percent in the final detector phase. RES-NOVA will be sensitive to flavor-blind neutrinos from the diffuse SN neutrino background with an exposure of $620\mathrm{ton}·\mathrm{y}$. The proposed RES-NOVA project has the potential to lay down the foundations for a new generation of neutrino telescopes while relying on a very simple technological setup.

Dwarf spheroidal galaxy satellites of the Milky Way are prime targets for indirect detection of dark matter with gamma rays due to their proximity, high dark matter content, and absence of nonthermal emission processes. Recently, the Dark Energy Survey (DES) revealed the existence of new ultrafaint dwarf spheroidal galaxies in the southern-hemisphere sky, therefore ideally located for ground-based observations with the imaging atmospheric Cherenkov telescope array H.E.S.S. We present a search for very-high-energy ($E\gtrsim 100\mathrm{GeV}$) gamma-ray emission using H.E.S.S. observations carried out recently towards Reticulum II, Tucana II, Tucana III, Tucana IV, and Grus II satellites. No significant very-high-energy gamma-ray excess is found from the observations on any individual object nor in the combined analysis of all the datasets. Using the most recent modeling of the dark matter distribution in the dwarf galaxy halo, we compute for the first time on DES satellites individual and combined constraints from Cherenkov telescope observations on the annihilation cross section of dark matter particles in the form of Weakly Interacting Massive Particles. The combined 95% C.L. observed upper limits reach $⟨\sigma v⟩\simeq 1\times {10}^{-23}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$ in the $W^{+}{W}^{-}$ channel and $4\times {10}^{-26}{\mathrm{cm}}^3{\mathrm{s}}^{-1}$ in the $\gamma \gamma$ channels for a dark matter mass of 1.5 TeV. The H.E.S.S. constraints well complement the results from Fermi-LAT, HAWC, MAGIC, and VERITAS and are currently the most stringent in the $\gamma \gamma$ channels in the multi-GeV/multi-TeV mass range.

The Jiangmen Underground Neutrino Observatory (JUNO) project aims at probing, at the same time, the two main frequencies of three-flavor neutrino oscillations, as well as their interference related to the mass ordering (normal or inverted), at a distance of $\sim 53\mathrm{km}$ from two powerful reactor complexes in China, at Yangjiang and Taishan. In the latter complex, the unoscillated spectrum from one reactor core is planned to be closely monitored by the Taishan Antineutrino Observatory (TAO), expected to have better resolution ($\times 1/2$) and higher statistics ($\times 30$) than JUNO. In the context of $\nu$ energy spectra endowed with fine-structure features from summation calculations, we analyze in detail the effects of energy resolution and nucleon recoil on observable event spectra. We show that a model spectrum in TAO can be mapped into a corresponding spectrum in JUNO through appropriate convolutions. The mapping is exact in the hypothetical case without oscillations and holds to a very good accuracy in the real case with oscillations. We then analyze the sensitivity to mass ordering of JUNO (and its precision oscillometry capabilities) assuming a single reference spectrum, as well as bundles of variant spectra, as obtained by changing nuclear input uncertainties in summation calculations from a publicly available toolkit. We show through an ${\chi }^2$ analysis that variant spectra induce little reduction of the sensitivity in JUNO, especially when TAO constraints are included. Subtle aspects of the statistical analysis of variant spectra are also discussed.

Recent literature has shown that photon-photon forward scattering mediated by Euler-Heisenberg interactions may generate some amount of the circular polarization ($V$ modes) in the cosmic microwave background (CMB) photons. However, there is an apparent contradiction among the different references about the predicted level of the amplitude of this circular polarization. In this work, we will resolve this discrepancy by showing that with a quantum Boltzmann equation formalism, we obtain the same amount of circular polarization as using a geometrical approach that is based on the index of refraction of the cosmological medium. We will show that the expected amplitude of $V$ modes is expected to be $\approx 8$ orders of magnitude smaller than the amplitude of $E$-polarization modes that we actually observe in the CMB, thus confirming that it is going to be challenging to observe such a signature. Throughout the paper, we also develop a general method to study the generation of $V$ modes from photon–photon and photon–spin-1-massive-particle forward scatterings without relying on a specific interaction, which thus represent possible new signatures of physics beyond the Standard Model.

We present a thorough phenomenological analysis of the experimental data from Belle Collaboration for the transverse $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ polarization, measured in $e^{+}{e}^{-}$ annihilation processes, for the case of associated (with a light charged hadron) and inclusive (plus a jet) production. Within a transverse momentum dependent (TMD) approach we show how this intriguing phenomenon can be accounted for. This allows for the first ever extraction of the quark polarizing fragmentation function for a $\mathrm{\Lambda }$ hyperon, a TMD distribution giving the probability that an unpolarized quark fragments into a transversely polarized spin-$1/2$ hadron.

Neutrino self-interactions ($\nu \mathrm{SI}$) beyond the Standard Model are an attractive possibility to soften cosmological constraints on neutrino properties and also to explain the tension in late and early time measurements of the Hubble expansion rate. The required strength of $\nu \mathrm{SI}$ to explain the $4\sigma$ Hubble tension is in terms of a pointlike effective four-fermion coupling that can be as high as ${10}^9{G}_F$, where $G_F$ is the Fermi constant. In this work, we show that such strong $\nu \mathrm{SI}$ can cause significant effects in two-neutrino double beta decay, leading to an observable enhancement of decay rates and to spectrum distortions. We analyze self-interactions via an effective operator as well as when mediated by a light scalar. Data from observed two-neutrino double beta decay are used to constrain $\nu \mathrm{SI}$, which rules out the regime around ${10}^9{G}_F$.

In the context of the surface-state correspondence we propose the geodesic curvature of a convex curve as a local measure of factorization of the dual Conformal Field Theory state. Its integral will be interpreted as computing the total bipartite entanglement among degrees of freedom with support on the chosen domain. We will derive results through application of the Gauss-Bonnet theorem and show quantitative agreement with computations using the Multiscale Entanglement Renormalization Ansatz tensor network and the formalism of entanglement density.

Motivated by $T\overline{T}$, we introduce and study a wide class of solvable deformations of quantum-mechanical theories. These deformations map the Hamiltonian to a function of itself. We solve these theories by computing all finite-temperature correlation functions of the deformed theory in terms of the correlators of the undeformed theory. Applications to $\mathrm{AdS}/\mathrm{CFT}$, Sachdev-Ye-Kitaev, and the Schwarzian theory are considered. We write down the deformed Schwarzian action for an arbitrary Hamiltonian deformation and find that the maximal Lyapunov exponent is unchanged.

We investigate in the context of the scattering equations, how one-loop linear propagator integrands in gauge theories can be linked to integrands with quadratic propagators using a double forward limit. We illustrate our procedure through examples and demonstrate how the different parts of the derived quadratic integrand are consistent with cut-integrands derived from four-dimensional generalized unitarity. We also comment on applications and discuss possible further generalizations.

We introduce a variation of the Bose-Einstein condensate(BEC)-Skyrme model, with an altered potential for miscible BECs that gives rise to two physical vortex strings. In the ground state of each topological sector, the vortices are linked exactly $B$ times, due to a recently formulated theorem, with $B$ being the baryon number of the solution. The model also possesses metastable states, where the vortices are degenerate and do not lend the interpretation of the baryon number as the linking number of the vortices.

In this work, we calculate the polar gravitational quasinormal modes for a quantum corrected black hole model, which arises in the context of loop quantum gravity, known as a self-dual black hole. In this way, we calculate the characteristic frequencies using the Wentzel-Kramers-Brillouin approach, where we can verify a strong dependence with the loop quantum gravity parameters. At the same time, we check that the self-dual black hole is stable under polar gravitational perturbations, and we can also verify that the spectrum of the polar quasinormal modes differs from the axial one [M. B. Cruz, C. A. S. Silva, and F. A. Brito, Eur. Phys. J. C 79, 157 (2019)]. Such a result tells us that isospectrality is broken in the context of self-dual black holes.

Positivity bounds provide conditions that a consistent UV completion exists for a quantum field theory. We examine their application to Horndeski theory with the luminal propagation speed of gravitational waves, reconstructed from the effective field theory (EFT) of dark energy. This enables us to assess whether particular phenomenological parametrizations of the EFT functions reconstruct theories that respect or violate the positivity bounds. We find that commonly adopted EFT parametrizations, cast in terms of the dark energy density or power laws of the scale factor, only satisfy the positivity bounds in nontrivial regions of the parameter space. We then examine parametrizations of the inherently stable EFT basis, constructed to avoid gradient and ghost instabilities by default. In stark contrast, in this basis, the positivity bounds either only provide constraints in a priori unrealistic regions of the parameter space or do not provide any constraints on parameter values at all. The application of positivity bounds to common parametrizations of the standard EFT functions can therefore lead to the artificial conclusions that the region of viable Horndeski modifications of gravity is highly constrained. Our results provide a strong motivation, in addition to the default avoidance of theoretical instabilities, for instead adopting parametrizations of the inherently stable EFT basis when testing dark energy and modified gravity models with forthcoming cosmological survey data.

We study the tidal deformations of various known black hole and wormhole solutions in a simple context of warped compactification—Randall-Sundrum theory—in which the four-dimensional spacetime geometry is that of a brane embedded in five-dimensional anti–de Sitter spacetime. The linearized gravitational perturbation theory generically reduces to either an inhomogeneous second-order ordinary differential equation (ODE) or a homogeneous third-order ODE for which indicial roots associated with an expansion about asymptotic infinity can be related to tidal Love numbers. We describe various tidal-deformed metrics, classify their indicial roots, and find, in particular, that the quadrupolar tidal Love number is generically nonvanishing. Thus, it could be a signature of a braneworld by virtue of its potential appearance in gravitational waveforms emitted in binary merger events.

A general relativistic solution, composed of a Zel’dovich-Letelier interior made of radial strings matched through a spherical thin shell at radius $r_0$ to an exterior Schwarzschild solution with mass $m$, is presented. It is the Zel’dovich-Letelier-Schwarzschild star. When the radius $r_0$ of the star is shrunk to its own gravitational radius $2m$, $r_0=2m$, the solutions that appear have very interesting properties. There are solutions with $m=0$ and $r_0=0$ that further obey $\frac{2m}{r_0}=1$. These solutions have a horizon, but they are not exactly black holes; they are quasiblack holes, though atypical ones. Moreover, the proper mass $m_p$ of the interior is nonzero and made of one string. Hence, a Minkowski exterior space hides an interior with matter in a pit. These are the pit solutions. These pits thus show a maximal mass defect. There are two classes of pit solutions: the first encloses a finite string and the second a semi-infinite one. These pits are really string pits, which can be seen as Wheeler bags of gold, albeit totally squashed bags. There is also another class, which is a compact stringy star at the $\frac{2m}{r_0}=1$ limit with $m$, and thus $r_0$, nonzero. It is a typical quasiblack hole and it also shows maximal mass defect. A generic analysis is presented that shows that pit solutions with $\frac{2m}{r_0}=1$ and $m=0$ can exist displaying maximal mass defect. The Zel’dovich-Letelier-Schwarzschild star at the $r_0=2m$ limit is actually an instance of the generic case. Notably, these three classes of static solutions yield the same spectrum of solutions that appear in critical gravitational collapse—namely, there are solutions that yield naked null singularities, which here are the two string pit classes of solutions, and there are solutions that yield black holes, which here are represented by the class of compact stringy stars at the quasiblack hole limit, the solutions that disperse away in critical gravitational collapse here are the static Zel’dovich-Letelier-Schwarzschild stars themselves. A thermodynamic treatment of the string pit and stringy star quasiblack hole solutions is provided, and connections to other solutions are mentioned.

This article describes the dynamics of a charged particle in an electromagnetic field in presence of a scalar fifth force. Focusing to the fifth force that would be induced by a chameleon field, the profile of which can be designed properly in the laboratory, it draws its physical effects on the cyclotron motion of a particle in a static and uniform magnetic field. The fifth force induces a drift of the trajectory that is estimated analytically and compared to numerical computations for profiles motivated by the ones of a chameleon field within two nested cylinders. The magnitude of the effect and the detectability of this drift are discussed to argue that this may offer a new experimental design to test small fifth force in the laboratory. More important, at the macroscopic level it induces a current that can in principle also be measured, and would even allow one to access the transverse profile of the scalar field within the cavity. In both cases, aligning the magnetic field with the local gravity field suppresses the effects of Newtonian gravity that would be several orders larger than the ones of the fifth force otherwise and the Newtonian gravity of the cavity on the particle is also argued to be negligible. Given this insight, this experimental setup, with its two effects—on a single particle and at the macroscopic level—may require attention to demonstrate its actual feasibility in the laboratory.

We demonstrate that Einstein’s general relativity theory arises as a special case in the framework of the Poincaré gauge theory of gravity under the assumption of a suitable nonminimal coupling of matter to the Riemann-Cartan geometry of spacetime.

The sonic point/photon surface correspondence is thoroughly investigated in a general setting. First, we investigate a sonic point of a transonic steady perfect fluid flow in a general stationary spacetime, particularly focusing on the radiation fluid. The necessary conditions that the flow must satisfy at a sonic point are derived as conditions for the kinematical quantities of the congruence of streamlines in analogy with the de Laval nozzle equation in fluid mechanics. We compare the conditions for a sonic point with the notion of a photon surface, which can be defined as a timelike totally umbilical hypersurface. As a result, we find that, for the realization of the sonic point/photon surface correspondence, the speed of sound $v_{\mathrm{s}}$ must be given by $1/\sqrt{d}$ with $d$ being the spatial dimension of the spacetime. For the radiation fluid ($v_{\mathrm{s}}=1/\sqrt{d}$), we confirm that a part of the conditions is shared by the sonic point and the photon surface. However, in general, a Bondi surface, a set of sonic points, does not necessarily coincide with a photon surface. Additional assumptions, such as a spatial symmetry, are essential to the realization of the sonic point/photon surface correspondence in all known examples.

Gravitational-wave observations of coalescing binary systems allow for novel tests of the strong-field regime of gravity. Using data from the Gravitational Wave Open Science Center (GWOSC) of the LIGO and Virgo detectors, we place the first constraints on an effective-field-theory based extension of general relativity, in which only higher-order curvature terms are added to the Einstein-Hilbert action. We construct gravitational-wave templates describing the quasicircular, adiabatic inspiral phase of binary black holes in this extended theory of gravity. Then, after explaining how to properly take into account the region of validity of the effective field theory when performing tests of general relativity, we perform Bayesian model selection using the two lowest-mass binary-black-hole events reported to date by LIGO and Virgo—GW151226 and GW170608—and constrain this theory with respect to general relativity. We find that these data disfavor the appearance of new physics on distance scales around $\sim 150\mathrm{km}$. Finally, we describe a general strategy for improving constraints as more observations will become available with future detectors on the ground and in space.

As gravitational-wave detectors become more sensitive and broaden their frequency bandwidth, we will access a greater variety of signals emitted by compact binary systems, shedding light on their astrophysical origin and environment. A key physical effect that can distinguish among different formation scenarios is the misalignment of the spins with the orbital angular momentum, causing the spins and the binary’s orbital plane to precess. To accurately model such precessing signals, especially when masses and spins vary in the wide astrophysical range, it is crucial to include multipoles beyond the dominant quadrupole. Here, we develop the first multipolar precessing waveform model in the effective-one-body (EOB) formalism for the entire coalescence stage (i.e., inspiral, merger and ringdown) of binary black holes: SEOBNRv4PHM. In the nonprecessing limit, the model reduces to SEOBNRv4HM, which was calibrated to numerical-relativity (NR) simulations, and waveforms from black-hole perturbation theory. We validate SEOBNRv4PHM by comparing it to the public catalog of 1405 precessing NR waveforms of the Simulating eXtreme Spacetimes (SXS) collaboration, and also to 118 SXS precessing NR waveforms, produced as part of this project, which span mass ratios 1-4 and (dimensionless) black-hole’s spins up to 0.9. We stress that SEOBNRv4PHM is not calibrated to NR simulations in the precessing sector. We compute the unfaithfulness against the 1523 SXS precessing NR waveforms, and find that, for 94% (57%) of the cases, the maximum value, in the total mass range $20-200M_{\odot }$, is below 3% (1%). Those numbers change to 83% (20%) when using the inspiral-merger-ringdown, multipolar, precessing phenomenological model IMRPhenomPv3HM. We investigate the impact of such unfaithfulness values with two Bayesian, parameter-estimation studies on synthetic signals. We also compute the unfaithfulness between those waveform models as a function of the mass and spin parameters to identify in which part of the parameter space they differ the most. We validate them also against the multipolar, precessing NR surrogate model NRSur7dq4, and find that the SEOBNRv4PHM model outperforms IMRPhenomPv3HM.

We investigate the second-order gravitational scalar perturbations for a barotropic fluid. We derive the effective energy-momentum tensor described by the quadratic terms of the gravitational and the matter perturbations. We show that the second-order effective energy-momentum tensor is gauge dependent. We impose three gauge conditions (longitudinal, spatially flat, and comoving gauges) for radiation and dust. The resulting energy-momentum tensor is described only by a gauge-invariant variable, but the functional form depends on the gauge choice. In the matter-dominated epoch with dustlike fluid background, the second-order effective energy density and pressure of the perturbations evolve as $1/a^2$ in all three gauge choices, like the curvature density of the Universe, but they do not provide the correct equation of state. The value of this parameter depends also on the gauge choice. In the radiation-dominated epoch, the perturbations in the short-wave limit behave in the same way as the radiationlike fluid in the longitudinal and the spatially flat gauges. However, they behave in a different way in the comoving gauge. As a whole, we conclude that the second-order effective energy-momentum tensor of the scalar perturbation is strictly gauge dependent.