Minkowski functionals quantify the morphology of smooth random fields. They are widely used to probe statistical properties of cosmological fields. Analytic formulas for ensemble expectations of Minkowski functionals are well known for Gaussian and mildly non-Gaussian fields. In this paper, we extend the formulas to composite fields which are sums of two fields and explicitly derive the expressions for the sum of uncorrelated mildly non-Gaussian and Gaussian fields. These formulas are applicable to observed data which is usually a sum of the true signal and one or more secondary fields that can be either noise, or some residual contaminating signal. Our formulas provide explicit quantification of the effect of the secondary field on the morphology and statistical nature of the true signal. As examples, we apply the formulas to determine how the presence of Gaussian noise can bias the morphological properties and statistical nature of Gaussian and non-Gaussian cosmic microwave background temperature maps.

In light of the nonperturbative resonance effects that may occur during inflation, we introduce a parametrization for the power spectrum of the stochastic gravitational wave background characterized by narrow-band amplification. We utilize the universal ${\mathrm{\Omega }}_{\mathrm{GW}}\propto k^3$ infrared limit, applicable to a wide array of gravitational wave sources, to devise a robust yet straightforward parametrization optimized for Markov chain Monte Carlo analyses. This parametrization is demonstrated through select examples where its application is pertinent, and we discuss the advantages of this approach over traditional parametrizations for narrow-band scenarios. To evaluate the sensitivity of our proposed model parameters, we apply a mock likelihood based on the CMB-Stage4 data. Furthermore, we explicate the computational process for the mapping relationship between the foundational model parameters and our parametrized framework, using a two-field inflation model that resonantly amplifies gravitational waves as an example.

We present a systematic study of cosmological parameter bias in weak lensing and large-scale structure analyses for upcoming imaging surveys induced by the interplay of intrinsic alignments (IA) and photometric redshift (photo-z) model misspecification error. We first examine the degeneracies between the parameters of the tidal alignment–tidal torquing (TATT) model for IA and of a photo-z model including a mean shift ($\mathrm{\Delta }\overline{z}$) and variance (${\sigma }_z$) for each tomographic bin of lenses and sources, under a variety of underlying true IA behaviors. We identify strong degeneracies between: (1) the redshift scaling of the tidal alignment amplitude and the mean shift and variances of source bins, (2) the redshift scaling of the tidal torquing amplitude and the variance of the lowest-$z$ source bin, and (3) the IA source density weighting and the mean shift and variance of several source bins. We then use this information to guide our exploration of the level of cosmological parameter bias which can be induced given incorrect modeling of IA, photo-z, or both. We find that marginalizing over all the parameters of TATT is generally sufficient to preclude cosmological parameter bias in the scenarios we consider. However, this does not necessarily mean that IA and photo-z parameters are themselves unbiased, nor does it mean that the best-fit model is a good fit to the data. We also find scenarios where the inferred parameters produce ${\chi }_{\mathrm{d}.\mathrm{o}.\mathrm{f}.}^2$ values indicative of a good fit but cosmological parameter bias is significant, particularly when the IA source density weighting parameter is not marginalized over.

The classical field approximation is widely used to better understand the predictions of ultralight dark matter. Here, we use the truncated Wigner approximation method to test the classical field approximation of ultralight dark matter. This method approximates a quantum state as an ensemble of independently evolving realizations drawn from its Wigner function. The method is highly parallelizable and allows the direct simulation of quantum corrections and decoherence times in systems many times larger than have been previously studied in reference to ultralight dark matter. Our study involves simulation of systems in 1, 2, and 3 spatial dimensions. We simulate three systems, the condensation of a Gaussian random field in three spatial dimensions, a stable collapsed object in three spatial dimensions, and the merging of two stable objects in two spatial dimensions. We study the quantum corrections to the classical field theory in each case. We find that quantum corrections grow exponentially during nonlinear growth with the timescale being approximately equal to the system dynamical time. In stable systems the corrections grow quadratically. We also find that the primary effect of quantum corrections is to reduce the amplitude of fluctuations on the de Broglie scale in the spatial density. Finally, we find that the timescale associated with decoherence due to gravitational coupling to baryonic matter is at least as fast as the quantum corrections due to gravitational interactions. These results are consistent with the predictions of the classical field theory being accurate.

Gamma-ray observations of Milky Way dwarf galaxies have been used to place stringent constraints on the dark matter’s annihilation cross section. In this paper, we evaluate the sensitivity of the proposed Advanced Particle-Astrophysics Telescope (APT) to dark matter in these systems, finding that such an instrument would be capable of constraining thermal relics with masses as large as $m_X\sim 600\mathrm{GeV}$. Furthermore, in dark matter scenarios motivated by the observed Galactic Center gamma-ray excess, we predict that APT would detect several dwarf galaxies with high significance. Such observations could be used to test the predicted proportionality between the gamma-ray fluxes and $J$-factors of individual dwarf galaxies, providing us with an unambiguous test of the origin of the Galactic Center excess.

We assert that nonlinear features of fast neutrino-flavor conversion (FFC) can be qualitatively different between core-collapse supernovae (CCSNe) and binary neutron star mergers (BNSMs). This argument arises from recent global FFC simulations in BNSM, in which fast flavor swap (FFS) emerges in very narrow spatial regions, whereas neutrinos in CCSN tend to evolve toward flavor equipartition. In this paper, we provide the physical mechanism of FFS based on a colliding neutrino beam model. Neutrinos/antineutrinos can undergo FFS when they propagate in ambient neutrino gas that propagates in the opposite direction and also has the opposite sign of ELN-XLN, where ELN and XLN denote electron- and heavy-leptonic neutrino number, respectively. Such environments can be naturally realized in BNSMs, whereas they are unlikely in CCSNe unless the neutrino sphere is strongly deformed aspherically. Our study exhibits the diversity of nonlinear dynamics of FFC.

Compact objects such as neutron stars and white dwarfs can source axionlike particles and QCD axions due to $CP$-violating axion-fermion couplings. The magnitude of the axion field depends on the stellar density and on the strength of the axion-fermion couplings. We show that even $CP$-violating couplings one order of magnitude smaller than existing constraints source extended axion field configurations. For axionlike particles, the axion energy is comparable to the magnetic energy in neutron stars with inferred magnetic fields of the order of ${10}^{13}\mathrm{G}$ and exceeds by more than one order of magnitude the magnetic energy content of white dwarfs with inferred fields of the order of ${10}^4\mathrm{G}$. On the other hand, the energy stored in the QCD axion field is orders of magnitude lower due to the smallness of the predicted $CP$-violating couplings. It is shown that the sourced axion field can polarize the photons emitted from the stellar surface, and stimulate the production of photons with energies in the radio band.

Dispersion relations (DR) are known to be a powerful instrument for studying scattering amplitudes. In particular, they often apply to calculations in perturbative QCD and the Standard Model. We argue that applying DR to amplitudes with double-logarithmic (DL) contributions should be done with proper caution because DL terms are often infrared divergent. Ignoring this circumstance leads to incorrect results. As an example of such a situation, we consider applying DR to decays of on-shell $W$- and $Z$-bosons into fermion pairs in the double-logarithmic approximation.

We study the evolution of Abelian $U(1)$ electromagnetic as well as non-Abelian $SU(2)$ gauge fields, in the presence of spacetime oscillations. Analysis of the time evolution of Abelian gauge fields shows the presence of parametric resonance in spatial modes. A similar analysis in the case of non-Abelian gauge fields, in the linear approximation, shows the presence of the same resonant spatial modes. The resonant modes induce large fluctuations in physical observables including those that break the $CP$ symmetry. We also carry out time evolution of small random fluctuations of the gauge fields, using numerical simulations in $2+1$ and $3+1$ dimensions. These simulations help to study nonlinear effects in the case of non-Abelian gauge theories. Our results show that there is an increase in energy density with the coupling, at late times. These results suggest that gravitational waves may excite non-Abelian gauge fields more efficiently than electromagnetic fields. Also, gravitational waves in the early Universe and from the merger of neutron stars, black holes, etc., may enhance $CP$ violation and generate an imbalance in chiral charge distributions, magnetic fields, etc.

CMS and ATLAS have reported small excesses in the search for low-mass Higgs bosons in the diphoton decay channel at exactly the same mass, 95.4 GeV. These searches rely on improved analysis techniques, enhancing in particular the discrimination against the $Z\to e^{+}{e}^{-}$ background. In models beyond the Standard Model (SM) that extend the Higgs sector with triplets, doubly charged Higgs bosons are predicted which can contribute substantially to the diphoton decay rate of a light Higgs boson. The Georgi-Machacek (GM) Model is of particular interest in this context, since despite containing Higgs triplets it preserves the electroweak $\rho$-parameter to be 1 at the tree level. We show that within the GM model, a Higgs boson with a mass of $\sim 95\mathrm{GeV}$ with a diphoton decay rate as observed by CMS and ATLAS can be well-described. We discuss the diphoton excess in conjunction with an excess in the $b\overline{b}$ final state observed at LEP and an excess observed by CMS in the ditau final state, which have been found at comparable masses with local significances of about $2\sigma$ and $3\sigma$, respectively. The presence of a Higgs boson at about 95 GeV within the GM model would imply good prospects of the searches for additional light Higgs bosons. In particular, the observed excess in the diphoton channel would be expected to be correlated in the GM model with a light doubly charged Higgs boson in the mass range between 100 and 200 GeV, which motivates dedicated searches in upcoming LHC Runs.

Long-baseline neutrino oscillation experiments offer a unique laboratory to test the fundamental Lorentz symmetry, which is at the heart of both the standard model of particle and general relativity theory. The sidereal modulation in neutrino events will act as the smoking-gun experimental signature of Lorentz and $CPT$ violation. In this study, we investigate the impact of the sidereal effect on standard neutrino oscillation measurements within the context of the NuMI Off-Axis ${\nu }_e$ Appearance Experiment ($\mathrm{NO}\nu \mathrm{A}$) experiment. Additionally, we assess the sensitivity of the $\mathrm{NO}\nu \mathrm{A}$ experiment to detect Lorentz-violating interactions, taking into account the sidereal effect. Furthermore, we highlight the potential of the $\mathrm{NO}\nu \mathrm{A}$ experiment to set new constraints on anisotropic Lorentz-violating parameters.

Little Higgs models address the hierarchy problem by identifying the SM Higgs doublet as pseudo-Nambu-Goldstone bosons arising from global symmetries with collective breakings. These models are designed to address the little hierarchy problem up to a scale of $\mathrm{\Lambda }\sim \mathcal{O}(10)\mathrm{TeV}$. Consequently, these models necessitate an UV completion above this scale. On the other hand, conformal extensions of the Standard Model are intriguing because scales emerge as a consequence of dimensional transmutation. In this study, we present a unified framework in which the electroweak hierarchy problem is tackled through a conformal symmetry collectively broken around the TeV scale, offering an appealing UV completion for little Higgs models. Notably, this framework automatically ensures the presence of the required UV fixed points, eliminating the need for careful adjustments to the particle content of the theory. Moreover, this framework naturally addresses the flavor puzzles associated with composite or little Higgs models. Furthermore, we suggest that in this framework all known little Higgs models can be UV completed through conformal dynamics above the scale $\mathrm{\Lambda }$ up to arbitrary high scales.

High-order behavior of the perturbative expansion for short-distance observables in QCD is intimately related to the contributions of small momenta in the corresponding Feynman diagrams and this correspondence provides one with a useful tool to investigate power-suppressed nonperturbative corrections. We use this technique to study the structure of power corrections to parton quasi- and pseudo-GPDs which are used in lattice calculations of generalized parton distributions. As the main result, we predict the functional dependence of the leading power corrections to quasi(pseudo)-GPDs on $x$ variable for nonzero skewedness parameter $\xi$. The kinematic point $x=\pm \xi$ turns out to be special. We find that the nonperturbative corrections to quasi-GPDs at this point are suppressed by the first power of the hard scale only. These contributions come from soft momenta and have nothing to do with the known UV renormalon in the Wilson line. We also show that power corrections can be strongly suppressed by the normalization procedure.

The present study provides spectroscopic investigations of spin-$\frac{3}{2}$ $\mathrm{\Lambda }$ baryons with both positive and negative parities. The analysis mainly focuses on three states, namely $1P$, $2P$, and $2S$, and corresponding masses are calculated using the QCD sum rule method. To implement the method, we apply two types of interpolating currents with octet and singlet quantum numbers and compare the corresponding results with the reported masses of experimentally observed states. From the comparisons, it is extracted that the results of interpolating current with octet quantum numbers are in good agreement with the experimentally measured masses. The masses obtained with this interpolating current are $m=1513.64\pm 8.76\mathrm{MeV}$ for $1P$ state with $J^P={\frac{3}{2}}^{-}$, $m^{\prime }=1687.91\pm 0.31\mathrm{MeV}$ for $2P$ state with $J^P={\frac{3}{2}}^{-}$ and $\tilde{m}=1882.37\pm 11.95\mathrm{MeV}$ for $2S$ state with $J^P={\frac{3}{2}}^{+}$ and they are consistent with the experimental masses of $\mathrm{\Lambda }(1520)$, $\mathrm{\Lambda }(1690)$, and $\mathrm{\Lambda }(1890)$, respectively, which confirm their spin-parity quantum numbers. Besides, we calculate the corresponding current coupling constants, which are utilized as inputs in the calculations of different form factors defining the widths of the states under study.

We explore the role of parametrizations for nonperturbative QCD functions in global analyses, with a specific application to extending a phenomenological analysis of the parton distribution functions (PDFs) in the charged pion realized in the xFitter fitting framework. The parametrization dependence of PDFs in our pion fits substantially enlarges the uncertainties from the experimental sources estimated in the previous analyses. We systematically explore the parametrization dependence by employing a novel technique to automate generation of polynomial parametrizations for PDFs that makes use of Bézier curves. This technique is implemented in a c++ module fantômas that is included in the xFitter program. Our analysis reveals that the sea and gluon distributions in the pion are not well disentangled, even when considering measurements in leading-neutron deep inelastic scattering. For example, the pion PDF solutions with a vanishing gluon and large quark sea are still experimentally allowed, which elevates the importance of ongoing lattice and nonperturbative QCD calculations, together with the planned pion scattering experiments, for conclusive studies of the pion structure.

Interactions of charged leptons with nuclei and the naive tree-level kinematics of these processes are affected by radiation of photons induced by the QED nuclear medium. We evaluate cross section modifications at leading orders of the number of correlated interactions inside the nucleus, known as the opacity expansion. We derive results for soft and collinear types of the bremsstrahlung at the first three orders in opacity and generalize them to higher orders. We present the leading in opacity energy spectra of soft and collinear photons and radiative energy loss inside the nucleus for experiments with lepton kinematics in the GeV energy range. At leading power of the Glauber soft-collinear effective field theory, the soft radiation is further resummed to all orders both in opacity and in the electromagnetic coupling constant. We find that the soft and collinear medium-induced radiation is vacuumlike, and additional corrections are power suppressed. Despite the negligible modification to the induced photon spectra, the nuclear medium-induced radiation sizably affects the broadening of charged leptons in the direction orthogonal to their propagation.

Using $(2.712\pm 0.014)\times {10}^9\psi (3686)$ events collected by the BESIII detector operating at the BEPCII collider, we report the first observation of $\psi (3686)\to 3\varphi$ decay with a significance larger than $10\sigma$. The branching fraction of this decay is determined to be $(1.46\pm 0.05\pm 0.17)\times {10}^{-5}$, where the first uncertainty is statistical and the second is systematic. No significant structure is observed in the $\varphi \varphi$ invariant mass spectra.

We study the perturbative stability of Euclidean axion-dilaton wormholes that asymptotically approach flat space, both with a massless and a massive dilaton, and focus on homogeneous perturbations. We find massless wormholes to always be perturbatively stable. The phenomenologically more relevant case of a massive dilaton presents us with a wide variety of wormhole solutions, depending on the dilaton coupling and mass, and on the axion charge. We find that the solutions with the smallest dilaton potential are perturbatively stable and dominant, even in cases where the wormhole solutions are not continuously connected to the massless case by decreasing the mass. For branches of solutions emanating from a bifurcation point, one side of the branch always contains a negative mode in its spectrum, rendering such solutions unstable. The existence of classes of perturbatively stable wormhole solutions with massive dilaton sharpens the puzzles associated with Euclidean wormholes.

The catastrophic decay of a spacetime with compact dimensions, via bubbles of nothing (BoNs), is probably a generic phenomenon. BoNs admit a four-dimensional description as singular Coleman–de Luccia bounces of the size modulus field, stabilized by some potential $V(\varphi )$. We apply the tunneling potential approach to this 4D description to provide a very simple picture of BoNs. Using it, we identify four different types of BoN, corresponding to different classes of higher-dimensional theories. We also identify 4D theories featuring a new type of quenching of BoN decay, which may be present even for dS vacua, and discuss the viability of embedding such models in a higher-dimensional theory. The present approach allows us to treat in a single framework BoN nucleation and other decay channels, and we study the interplay between the different nonperturbative instabilities comparing their decay rates.

One approach to testing general relativity (GR) introduces free parameters in the post-Newtonian (PN) expansion of the gravitational-wave (GW) phase. If systematic errors on these testing GR (TGR) parameters exceed the statistical errors, this may signal a false violation of GR. Here, we consider systematic errors produced by unmodeled binary eccentricity. Since the eccentricity of GW events in ground-based detectors is expected to be small or negligible, the use of quasicircular waveform models for testing GR may be safe when analyzing a small number of events. However, as the catalog size of GW detections increases, more stringent bounds on GR deviations can be placed by combining information from multiple events. In that case, even small systematic biases may become significant. We apply the approach of hierarchical Bayesian inference to model the posterior probability distributions of the TGR parameters inferred from a population of eccentric binary black holes (BBHs). We assume each TGR parameter value varies across the BBH population according to a Gaussian distribution. The means and standard deviations that parametrize these Gaussians are related to the statistical and systematic errors measured for each BBH event. We compute the posterior distributions for these Gaussian hyperparameters, characterizing the BBH population via three possible eccentricity distributions. This is done for LIGO and Cosmic Explorer (CE, a proposed third-generation detector). We find that systematic biases from unmodeled eccentricity can signal false GR violations for both detectors when considering constraints set by a catalog of events. We also compute the projected bounds on the 10 TGR parameters when eccentricity is included as a parameter in the waveform model. This is done via multiplying the individual likelihoods for each event in the catalog, and also by combining them via hierarchical inference. We find that the first four dimensionless TGR deformation parameters can be bounded at 90% confidence to $\delta {\widehat{\phi }}_i\lesssim {10}^{-2}$ for LIGO and $\lesssim {10}^{-3}$ for CE [where $i=(0,1,2,3)$; GR predicts zero for all values of the $\delta {\widehat{\phi }}_i$]. The most stringent bound applies to the $-1\mathrm{PN}$ (dipole) parameter: it is constrained to $|\delta {\widehat{\phi }}_{-2}|\lesssim {10}^{-5}$ ($\lesssim 4\times {10}^{-7}$) by LIGO (CE). In comparison to the circular orbit case, the combined bounds on the TGR parameters worsen by a modest factor of $\lesssim 2$ when eccentricity is included in the waveform. (The dipole parameter bound degrades by a factor of $\sim 3–4$ in this case).