Over the last years some interest has been gathered by $f(Q)$ theories, which are new candidates to replace Einstein’s prescription for gravity. The nonmetricity tensor $Q$ allows to put forward the assumption of a free torsionless connection and, consequently, new degrees of freedom in the action are taken into account. This work focuses on a class of $f(Q)$ theories, characterized by the presence of a general power-law term which adds up to the standard (linear in) $Q$ term in the action, and on new cosmological scenarios arising from them. Using the Markov chain Monte Carlo method, we carry out statistical tests relying upon background data such as Type Ia supernovae luminosities and direct Hubble data (from cosmic clocks), along with cosmic microwave background shift and baryon acoustic oscillations data. This allows us to perform a multifaceted comparison between these new cosmologies and the (concordance) $\mathrm{\Lambda }\mathrm{CDM}$ setup. We conclude that, at the current precision level, the best fits of our $f(Q)$ models correspond to values of their specific parameters which make them hardly distinguishable from our general relativity “échantillon,” that is, $\mathrm{\Lambda }\mathrm{CDM}$.

We investigate the multi-azimuthal angle (MAA) effect on collective neutrino oscillation by considering the three-dimensional neutrino momentum distribution in a realistic electron-capture supernova model with an $8.8M_{\odot }$ progenitor. We find that the MAA effect induces collective flavor conversions at epochs when it is completely suppressed under the axial-symmetric approximation. This novel activity is switched on/off by the growth of the MAA instability and imprints additional time evolution in the expected neutrino event rate. We validate our results by extending the linear stability analysis into the three-flavor scheme including mixing angles, and confirm that the onset of collective neutrino oscillation matches the steep growth of flavor instability. We discuss how the MAA effect alters neutrino detection at Super-Kamiokande and DUNE.

We revisit the sensitivity to nonresonant, heavy Majorana neutrinos $N$ in same-sign $W^{\pm }{W}^{\pm }$ scattering at the $\sqrt{s}=13\mathrm{TeV}$ LHC and its high-luminosity upgrade. As a benchmark scenario, we work in the context of the phenomenological type I seesaw model, relying on a simulation up to next-to-leading order in QCD with parton shower matching. After extensively studying the phenomenology of the $pp\to {\mu }^{\pm }{\mu }^{\pm }jj$ process at the amplitude and differential levels, we design a simple collider analysis with remarkable signal-background separation power. At 95% confidence level we find that the squared muon-heavy neutrino mixing element $|V_{\mu N}{|}^2$ can be probed down to about 0.06–0.3(0.03–0.1) for $m_N=1–10\mathrm{TeV}$ with $\mathcal{L}=300{\mathrm{fb}}^{-1}(3{\mathrm{ab}}^{-1})$. For heavier masses of $m_N=20\mathrm{TeV}$, we report sensitivity for $|V_{\mu N}{|}^2\gtrsim 0.5(0.3)$. The $W^{\pm }{W}^{\pm }$ scattering channel can greatly extend the mass range covered by current LHC searches for heavy Majorana neutrinos and particularly adds invaluable sensitivity above a few hundred GeV. We comment on areas where the analysis can be improved as well as on the applicability to other tests of neutrino mass models.

We extract the neutron electric dipole moment $|{\overrightarrow{d}}_N|$ within the lattice QCD formalism. We analyze one ensemble of $N_f=2+1+1$ twisted mass clover-improved fermions with lattice spacing of $a\simeq 0.08\mathrm{fm}$ and physical values of the quark masses corresponding to a pion mass $m_{\pi }\simeq 139\mathrm{MeV}$. The neutron electric dipole moment is extracted by computing the $CP$-odd electromagnetic form factor $F_3(Q^2\to 0)$ through small $\theta$-expansion of the action. This approach requires the calculation of the topological charge for which we employ a fermionic definition by means of spectral projectors while we also provide a comparison with the gluonic definition accompanied by the gradient flow. We show that using the topological charge from spectral projectors leads to absolute errors that are more than two times smaller than those provided when the field theoretic definition is employed. We find a value of $|{\overrightarrow{d}}_N|=0.0009(24)\theta e·\mathrm{fm}$ when using the fermionic definition, which is statistically consistent with zero.

The MiniBooNE experiment at Fermilab reports a total excess of $638.0\pm 52.1(\mathrm{stat}.)\pm 122.2(\mathrm{syst}.)$ electronlike events from a data sample corresponding to $18.75\times {10}^{20}$ protons-on-target in neutrino mode, which is a 46% increase in the data sample with respect to previously published results and $11.27\times {10}^{20}$ protons-on-target in antineutrino mode. The overall significance of the excess, $4.8\sigma$, is limited by systematic uncertainties, assumed to be Gaussian, as the statistical significance of the excess is $12.2\sigma$. The additional statistics allow several studies to address questions on the source of the excess. First, we provide two-dimensional plots in visible energy and the cosine of the angle of the outgoing lepton, which can provide valuable input to models for the event excess. Second, we test whether the excess may arise from photons that enter the detector from external events or photons exiting the detector from ${\pi }^0$ decays in two model independent ways. Beam timing information shows that almost all of the excess is in time with neutrinos that interact in the detector. The radius distribution shows that the excess is distributed throughout the volume, while tighter cuts on the fiducial volume increase the significance of the excess. The data likelihood ratio disfavors models that explain the event excess due to entering or exiting photons.

In everyday research, it is tacitly assumed that scattering cross sections have fixed values for a given particle species, center-of-mass energy, and particle polarization. However, this assumption has been called into question after several observations of suppression of high-energy bremsstrahlung. This process will play a major role in experiments at the future Electron-Ion Collider, and we show how variations of the bremsstrahlung cross section can be profoundly studied there using the lateral beam displacements. In particular, we predict a very strong increase of the observed cross sections for large beam separations. We also discuss the relation of these elusive effects to other quantum phenomena occurring over macroscopic distances. In this context, spectacular and possibly useful properties of the coherent bremsstrahlung at the Electron-Ion Collider are also evaluated.

We derive a formula for the total canonical energy, and its flux, of weak gravitational waves on a de Sitter background.

Close stellar binaries are prone to undergo a phase of stable mass transfer in which a star loses mass to its companion. Assuming that the donor star loses mass along the instantaneous interstellar axis, we derive the orbit-averaged equations of motion describing the evolution of the donor rotational angular momentum vector (spin) that accompanies the transfer of mass. We consider: (i) a model in which the mass transfer rate is constant within each orbit and (ii) a phase-dependent rate in which all mass per orbit is lost at periapsis. In both cases, we find that the ejection of $\gtrsim 30$ percent of the donor’s initial mass causes its spin to nearly flip onto the orbital plane of the binary, independently of the initial spin-orbit alignment. Moreover, we show that the spin flip due to mass transfer can easily dominate over tidal synchronization in any giant stars and main-sequence stars with masses $\sim 1.5$ to $5{\mathrm{M}}_{\odot }$. Finally, the general equations of motion, including tides, are used to evolve a realistic population of massive binary stars, leading to the formation of binary black holes. Assuming that the stellar core and envelope are fully coupled, the resulting tilt of the first-born black hole reduces its spin projection onto the orbit normal by a factor $\sim \mathcal{O}(0.1)$. This result supports previous studies in favor of an insignificant contribution to the effective spin projection, ${\chi }_{\mathrm{eff}}$, in binary black holes formed from the evolution of field binaries.

The eventual detection of gravitational waves from core-collapse supernovae (CCSNe) will help improve our current understanding of the explosion mechanism of massive stars. The stochastic nature of the late postbounce gravitational wave signal due to the nonlinear dynamics of the matter involved and the large number of degrees of freedom of the phenomenon make the source parameter inference problem very challenging. In this paper we take a step towards that goal and present a parameter estimation approach which is based on the gravitational waves associated with oscillations of protoneutron stars (PNS). Numerical simulations of CCSN have shown that buoyancy-driven $g$ modes are responsible for a significant fraction of the gravitational wave signal and their time-frequency evolution is linked to the physical properties of the compact remnant through universal relations. We use a set of 1D CCSN simulations to build a model that relates the evolution of the PNS properties with the frequency of the dominant $g$ mode, which is extracted from the gravitational-wave data using a new algorithm we have developed for our study. The model is used to infer the time evolution of a combination of the mass and the radius of the PNS. The performance of the method is estimated employing simulations of 2D CCSN waveforms covering a progenitor mass range between 11 and 40 solar masses and different equations of state. Considering signals embedded in Gaussian gravitational wave detector noise, we show that it is possible to infer PNS properties for a galactic source using Advanced LIGO and Advanced Virgo data at design sensitivities. Third generation detectors such as Einstein Telescope and Cosmic Explorer will allow us to test distances of $\mathcal{O}(100\mathrm{kpc})$.

We study the noncommutativity of different orders of zero energy-momentum limit pertaining to the axial chemical potential in the chiral magnetic effect. While this noncommutativity issue originates from the pinching singularity at one-loop order, it cannot be removed by introducing a damping term to the fermion propagators. The physical reason is that modifying the propagator alone would violate the axial-vector Ward identity and as a result a modification of the longitudinal component of the axial-vector vertex is required, which contributes to chiral magnetic effect (CME). The pinching singularity with free fermion propagators was then taken over by the singularity stemming from the dressed axial-vector vertex. We show this mechanism by a concrete example. Moreover, we proved, in general, the vanishing CME in the limit order that the static limit was taken prior to the homogeneous limit in the light of Coleman-Hill theorem for a static external magnetic field. For the opposite limit that the homogeneous limit is taken first, we show that the nonvanishing CME was a consequence of the nonrenormalization of chiral anomaly for an arbitrary external magnetic field.

Force potential exerting between two classical static sources of pure non-Abelian gauge theory in the Coulomb gauge is reconsidered at a periodic/twisted box of size $L^3$. Its perturbative behavior is examined by the short-distance expansion as well as by the derivative expansion. The latter expansion to one-loop order confirms the well-known change in the effective coupling constant at the Coulomb part as well as the Uehling potential while the former is given by the convolution of two Coulomb Green functions being nonsingular at $\mathit{x}=\mathit{y}$. The effect of the twist comes in through its Green function of the sector.

The usage of Monte Carlo neutrino event generators ($\mathrm{MC}\nu \mathrm{EG}\mathrm{s}$) is a norm within the high-energy $\nu$ scattering community. The relevance of quasielastic (QE) energy regimes to $\nu$ oscillation experiments implies that accurate calculations of $\nu A$ cross sections in this regime will be a key contributor to reducing the systematic uncertainties affecting the extraction of oscillation parameters. In spite of this, many $\mathrm{MC}\nu \mathrm{EG}\mathrm{s}$ utilize highly phenomenological, parametrized models of QE scattering cross sections. Moreover, a culture of validation of $\mathrm{MC}\nu \mathrm{EG}$s against prolific electron ($e$) scattering data has been historically lacking. In this work, we implement new $eA$ cross sections obtained from nuclear ab initio approaches in GENIE, the primary $\mathrm{MC}\nu \mathrm{EG}$ utilized by the FNAL community. In particular, we utilize results from quantum MC methods which solve the many-body nuclear problem in the short-time approximation (STA), allowing consistent retention of two-nucleon dynamics which are crucial to explain available nuclear electromagnetic (electroweak) data over a wide range of energy and momentum transfers. This new implementation in GENIE is fully tested against the world QE electromagnetic data, finding agreement with available data below $\sim 2\mathrm{GeV}$ of beam energy with the aid of a scaling function formalism. The STA is currently limited to study $A\le 12$ nuclei, however, its semi-inclusive multibody identity components are exportable to other many-body computational techniques such as auxiliary field diffusion MC which can reach $A\le 40$ systems while continuing to realize the factorization contained within the STA’s multinucleon dynamics. Together, these developments promise to make future experiments such as DUNE more accurate in their assessment of $\mathrm{MC}\nu \mathrm{EG}$ systematics, $\nu$ properties, and potentially empower the discovery of physics beyond the Standard Model.

A definition of nonequilibrium free energy ${\mathcal{F}}_{\mathrm{s}}$ is proposed for dynamical Gaussian quantum open systems strongly coupled to a heat bath and the formal relation with the generating functional, the coarse-grained effective action and the influence action is indicated. For Gaussian open quantum systems exemplified by the quantum Brownian motion model studied here, a time-varying effective temperature can be introduced in a natural way, and, with it, the nonequilibrium free energy ${\mathcal{F}}_{\mathrm{s}}$, von Neumann entropy ${\mathcal{S}}_{vN}$ and internal energy ${\mathcal{U}}_{\mathrm{s}}$ of the reduced system ($S$) can be defined accordingly. In contrast to the nonequilibrium free energy found in the literature which references the bath temperature, the nonequilibrium thermodynamic functions we find here obey the familiar relation ${\mathcal{F}}_{\mathrm{s}}(t)={\mathcal{U}}_{\mathrm{s}}(t)-T_{\mathrm{EFF}}(t){\mathcal{S}}_{vN}(t)$ at any and all moments of time in the system’s fully nonequilibrium evolution history. After the system equilibrates they coincide, in the weak coupling limit, with their counterparts in conventional equilibrium thermodynamics. Since the effective temperature captures both the state of the system and its interaction with the bath, upon the system’s equilibration, it approaches a value slightly higher than the initial bath temperature. Notably, it remains nonzero for a zero-temperature bath, signaling the existence of system-bath entanglement. Reasonably, at high bath temperatures and under ultraweak couplings, it becomes indistinguishable from the bath temperature. The nonequilibrium thermodynamic functions and relations discovered here for dynamical Gaussian quantum systems should open up useful pathways toward establishing meaningful theories of nonequilibrium quantum thermodynamics.

The availability of accurate numerical waveforms is an important requirement for the creation and calibration of reliable waveform models for gravitational wave astrophysics. For black hole-neutron star binaries (BHNS), very few accurate waveforms are however publicly available. Most recent models are calibrated to a large number of older simulations with good parameter space coverage for low-spin nonprecessing binaries but limited accuracy, and a much smaller number of longer, more recent simulations limited to nonspinning black holes. In this paper, we present long, accurate numerical waveforms for three new systems that include rapidly spinning black holes, and one precessing configuration. We study in detail the accuracy of the simulations, and in particular perform for the first time in the context of BHNS binaries a detailed comparison of waveform extrapolation methods to the results of Cauchy characteristic extraction. The new waveforms have $<0.1\mathrm{rad}$ phase errors during inspiral, rising to $\sim (0.2–0.4)\mathrm{rad}$ errors at merger, and $\lesssim 1\%$ error in their amplitude. We compute the faithfulness of recent analytical models to these numerical results for the late inspiral and merger phases covered by the numerical simulations, and find that models specifically designed for BHNS binaries perform well (faithfulness $F>0.99$) for binaries seen face on. For edge-on observations, particularly for precessing systems, disagreements between models and simulations increase, and models that include precession and/or higher-order modes start to perform better than BHNS models that currently lack these features.

Decay of the inflaton or moduli which dominated the energy density of the universe at early times leads to a matter to radiation transition epoch. We consider nonthermal sterile dark matter (DM) particles produced as decay product during such transitions. The particles have a characteristic energy distribution—that associated with decays taking place in a matter dominated universe evolving to radiation domination. We primarily focus on the case when the particles are hot dark matter, and study their effects on the cosmic microwave background (CMB) and large scale structure (LSS), explicitly taking into account their nonthermal momentum distribution. Our results for CMB angular power and linear matter power spectra reveal interesting features—such as an order of magnitude higher values of hot dark matter mass in comparison to the thermal case being consistent with the present data. We observe that this is related to the fact that $\mathrm{\Delta }{N}_{\mathrm{eff}}$ (the effective number of relativistic degrees of freedom at the time of CMB decoupling) and the hot DM energy density can be independent of each other unlike the case of thermal or nonresonantly produced sterile hot DM. We also find features in the CMB at low $\ell$ angular power potentially related to supersonic transmission of hot dark matter through the photon-baryon plasma.

Stimulated by the $P_{cs}(4459)$ reported by the LHCb collaboration, we perform a single ${\mathrm{\Xi }}_c{\overline{D}}^{*}$ channel and a coupled ${\mathrm{\Xi }}_c{\overline{D}}^{*}/{\mathrm{\Xi }}_c^{*}\overline{D}/{\mathrm{\Xi }}_c^{\prime }{\overline{D}}^{*}/{\mathrm{\Xi }}_c^{*}{\overline{D}}^{*}$ channel analysis by using a one-boson-exchange model. Our results indicate that the newly $P_{cs}(4459)$ cannot be a pure ${\mathrm{\Xi }}_c{\overline{D}}^{*}$ molecular state, but a coupled ${\mathrm{\Xi }}_c{\overline{D}}^{*}/{\mathrm{\Xi }}_c^{*}\overline{D}/{\mathrm{\Xi }}_c^{\prime }{\overline{D}}^{*}/{\mathrm{\Xi }}_c^{*}{\overline{D}}^{*}$ bound state with $I(J^P)=0(3/2^{-})$, where the ${\mathrm{\Xi }}_c{\overline{D}}^{*}$ and ${\mathrm{\Xi }}_c^{*}\overline{D}$ components are dominant. Meanwhile, we find the interactions from the ${\mathrm{\Xi }}_c^{\prime }{\overline{D}}^{*}$ system with $0(1/2^{-})$, the ${\mathrm{\Xi }}_c^{*}\overline{D}$ system with $1(3/2^{-})$, and the ${\mathrm{\Xi }}_c^{*}{\overline{D}}^{*}$ system with $1(1/2^{-})$ are strongly attractive, where one can expect possible strange hidden-charm molecular or resonant structures near these thresholds with the assigned quantum numbers.

We study the cobordism conjecture of McNamara and Vafa which asserts that the bordism group of quantum gravity is trivial. In the context of type IIB string theory compactified on a circle, this predicts the presence of D7-branes. On the other hand, the non-Abelian structure of the IIB duality group $SL(2,\mathbb{Z})$ implies the existence of additional $[p,q]$ 7-branes. We find that this additional information is instead captured by the space of closed paths on the moduli space of elliptic curves parameterizing distinct values of the type IIB axio-dilaton. This description allows to recover the full structure of non-Abelian braid statistics for 7-branes. Combining the cobordism conjecture with an earlier Swampland conjecture by Ooguri and Vafa, we argue that only certain congruence subgroups $\mathrm{\Gamma }\subset SL(2,\mathbb{Z})$ specifying genus zero modular curves can appear in 8D F-theory vacua. This leads to a successful prediction for the allowed Mordell–Weil torsion groups for 8D F-theory vacua.

Recent data from the Pierre Auger Observatory has revealed the presence of a large-scale dipole in the arrival direction distribution of ultrahigh-energy cosmic rays (UHECR). In this work, we build up an understanding of the diffusive origin of such a dipolar behavior as well as its dependency on energy and astrophysical source assumptions such as extra-Galactic magnetic field strength and cosmic ray composition. We present a novel analytical approach for calculating the angular distribution of CR coming from a single source and discuss the regimes in which the steady-state dipole result is expected. We also present a semianalytical method for calculating the evolution with energy of the resultant dipole for an ensemble of sources. We show that a local source allows for a strong growth of the dipole with energy over a large energy range. The possibility of a transition from a dipolar to nondipolar regime at the highest energies and its implications for the source density, magnetic field intensity, and cosmic ray composition are discussed.

In this work, we study the effect of (anti)kaon condensation on the properties of compact stars that develop hypernuclear cores with and without an admixture of $\mathrm{\Delta }$-resonances. We work within the covariant density functional theory with the parameters adjusted to $K$-atomic and kaon-nucleon scattering data in the kaonic sector. The density-dependent parameters in the hyperonic sector are adjusted to the data on $\mathrm{\Lambda }$ and ${\mathrm{\Xi }}^{-}$ hypernuclei data. The $\mathrm{\Delta }$-resonance couplings are tuned to the data obtained from their scattering off nuclei and heavy-ion collision experiments. We find that (anti)kaon condensate leads to a softening of the equation of state and lower maximum masses of compact stars than in the absence of the condensate. Both the $K^{-}$ and ${\overline{K}}^0$ condensations occur through a second-order phase transition, which implies no mixed-phase formation. For large values of (anti)kaon and $\mathrm{\Delta }$-resonance potentials in symmetric nuclear matter, we observe that condensation leads to an extinction of ${\mathrm{\Xi }}^{-,0}$ hyperons. We also investigate the influence of inclusion of additional hidden-strangeness ${\sigma }^{*}$ meson in the functional and find that it leads to a substantial softening of the equation of state and delay in the onset of (anti)kaons.

Analogous to the light-shining-through-wall setup proposed for axionlike particle searches, a pair of resonant cavities have been considered to search for an extra U(1) massive gauge boson, called a hidden photon, which mediates the interactions in the hidden sector. We propose a new cavity configuration, consisting of a cylindrical emitter surrounded by a hollow cylindrical detector to remarkably improve experimental sensitivity to hidden photon signals in the $\mu \mathrm{eV}$ mass range. An extensive study was conducted to find the optimal cavity geometry and resonant mode, which yields the best performance. In addition, a feasible application of superconducting rf technology was explored. We found the integration of these potential improvements will enhance the sensitivity to the effective kinetic mixing parameter between the hidden photon and the Standard Model photon by multiple orders of magnitude.