We present the expansion of stout smearing and the Wilson flow in lattice perturbation theory to order $g_0^3$, which is suitable for one-loop calculations. As the Wilson flow is generated by infinitesimal stout smearing steps, the results are related to each other by taking the appropriate limits. We show how to apply perturbative stout smearing or Wilson flow to the Feynman rules of any lattice fermion action and illustrate them by calculating the self-energy of the clover-improved Wilson fermion.

We discuss a general framework for the evaluation of the gluonic form factors in light hadrons at low momentum transfer, in the QCD instanton vacuum. At medium resolution of the order of the inverse mean instanton size, the glue is mostly localized in single or pairs of pseudoparticles and globally constrained by the fluctuations of their topological charges. These pseudoparticles trap light quarks, giving rise to emerging multiflavor ’t Hooft interactions. We explicitly evaluate the gluonic scalar, pseudoscalar, energy-momentum tensor (EMT), and the leading $C$-odd and $C$-even three-gluon hadronic form factors, at next to leading order in the instanton density, including molecular clusters of like and unlike instantons. We use the results for the EMT to address the contribution of the gluons in Ji’s mass and spin sum rules, at low resolution. When evolved, our results for the mass and spin composition of the nucleon are shown to be in good agreement with the recently reported lattice results at higher resolution.

This paper explores the calculation of nonperturbative parameters present in the matrix element of semileptonic inclusive $B$ decays. These are important for the inclusive determination of the Cabbibo-Kobayashi-Maskawa parameters in the Standard Model. We focus on calculating the rate for radiative inclusive decay, $B\to X_c\ell {\overline{\nu }}_{\ell }\gamma$, where $\gamma$ is hard. Both the radiative and nonradiative ($B\to X_c\ell {\overline{\nu }}_{\ell }$) modes are found to require the same nonperturbative parameters. We propose forming ratios from $B\to X_c\ell {\overline{\nu }}_{\ell }\gamma$ and $B\to X_c\ell {\overline{\nu }}_{\ell }$ widths in different lepton energy ranges. Our results provide an efficient way to unambiguously calculate the nonperturbative parameters, especially when combined with total width calculations of $B\to X_c\ell {\overline{\nu }}_{\ell }$. This is shown explicitly by working to $\mathcal{O}(1/m_b)$ and determining ${\lambda }_1$ and ${\lambda }_2$.

The decays of exotic states discovered experimentally always proceed via the strong and electromagnetic interactions. Recently, a tetraquark state with the quark content $bc\overline{q}\overline{q}$ was predicted by lattice QCD simulations. It is below the mass threshold of $D\overline{B}$, which can only decay via the weak interaction. In this work, based on the decay mechanism of $T_{cc}$ as a $D{D}^{*}$ molecule, we propose that the decays of the $bc\overline{q}\overline{q}$ tertaquark state as a $D\overline{B}$ molecule proceed via the Cabibbo-favored weak decays of the $\overline{B}$ or $D$ meson, accompanied by the tree-level decay modes and the triangle decay modes. Our results indicate that the branching fraction of the $D\overline{B}$ molecule decaying into ${\pi }^{+}{K}^{-}{\overline{B}}^0$ is sizable, which is a good channel to observe the $D\overline{B}$ molecule in future experiments.

Neutrinos with large self-interactions arising from exchange of light scalars or vectors with mass $M_{\varphi }\simeq 10\mathrm{MeV}$ can play a useful role in cosmology for structure formation and solving the Hubble tension. It has been proposed that large self-interactions of neutrinos may change the observed properties of supernova like the neutrino luminosity or the duration of the neutrino burst. In this paper, we compare the gravitational wave memory signal arising from supernova neutrinos. Our results reveal that memory signals for self-interacting neutrinos are weaker than free-streaming neutrinos in the high-frequency range. Implications for detecting and differentiating between such signals for planned space-borne detectors, Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) and Big Bang Observer (BBO), are also discussed.

We investigate the resonance phenomenon in deeply bound charmoniumlike states. By interpreting the $Y(4220)$, $Y(4360)$, and $\psi (4415)$ states as deeply $S$-wave bound $D{\overline{D}}_1$, $D^{*}{\overline{D}}_1$, and $D^{*}{\overline{D}}_2^{*}$ molecules, respectively, we robustly predict the existence of 4 $S$-wave deeply bound $C$-parity partner states and 13 $P$-wave charmoniumlike molecular resonances. These states, formed by exchanging the light mesons and pinpointed through the complex scaling method, include 3 $S$-wave bound states with exotic quantum numbers $I(J^{PC})=0(1^{-+})$ and 5 $P$-wave resonances with exotic $0(0^{-+})$ and $0(2^{+-})$. We expect future experiments to search for such exotic molecular resonances, which will not only enrich the ongoing construction of “Particle Zoo 2.0” but also help to scrutinize the hadronic molecular assignments of the $Y$- family particles including the $Y(4220)$, $Y(4360)$, and $\psi (4415)$ states.

In order to investigate the potential observational signals of different regularization ambiguities in loop quantum cosmological models, we systematically compute and compare the primordial scalar power spectra and the resulting angular power spectra in the standard loop quantum cosmology (LQC) and Thiemann regularized versions, modified LQC-I/II (mLQC-I/II), using both the dressed metric and the hybrid approaches. All three loop quantum cosmological models yield a nonsingular bounce with a postbounce physics that converges rapidly in a few Planck seconds. Using Starobinsky potential and the initial conditions for the background dynamics chosen to yield the same inflationary e-foldings, which are fixed to be 65 in all three LQC models, we require that all three models result in the same scale-invariant regime for the primordial power spectrum with a relative difference of less than 1%. This permits us to explore the differences resulting from the deep Planck regime in the angular power spectrum. For the adiabatic states, our results demonstrate that the angular power spectrum predicted by the hybrid approach has a smaller deviation from the angular power spectrum predicted by the standard $\mathrm{\Lambda }$ cold dark matter ($\mathrm{\Lambda }\mathrm{CDM}$) cosmological model at large angles in comparison with the dressed metric approach for all three models. The angular power spectrum predicted by mLQC-I in both the hybrid and the dressed metric approaches shows the smallest deviation from the one predicted by the standard $\mathrm{\Lambda }\mathrm{CDM}$ cosmological model at large angular scales, except for the case of fourth order adiabatic initial states in the hybrid approach. On the contrary, mLQC-II results in the largest deviations for the amplitude of the angular power spectrum at large angles and is most disfavored.

We study gravitational collapse in effective loop quantum gravity, focusing on nonmarginally bound configurations in Lemaître-Tolman-Bondi spacetimes. In the homogeneous limit we recover the effective dynamics of loop quantum cosmology for Friedman cosmologies with spatial curvature. We study a particular family of configurations with a homogeneous interior and a sharp boundary where the dust energy density rapidly and continuously decreases to zero. For these configurations, the gravitational collapse continues to the Planck regime when a bounce occurs, at which point the dust ball starts to expand, and a shock wave forms in the gravitational field within the order of a Planck time after the bounce. The shock slowly moves outward, eventually reaching the horizon which then disappears, at which time there is no longer a black hole. If the initial configuration is bound, the shock asymptotes to a maximal radius, whereas for unbound initial configurations the shock escapes to infinity. In all cases, the black hole lifetime is proportional to the square of the black hole mass, and additionally depends on how strongly bound the dust profile is; this last quantity also affects the vacuum region outside the dust profile which is not solely determined by the black hole mass and charge as in spherically symmetric general relativity. We also use numerics to study a wide range of other types of initial configurations, both bound and unbound, with qualitatively similar results.

We explore the classical Regge growth conjecture in the 4d effective field theory that results from compactifying $D$-dimensional general relativity on a compact, Ricci-flat manifold. While the higher dimensional description is given in terms of pure Einstein gravity and the conjecture is automatically satisfied, it imposes several nontrivial constraints in the 4d spectrum. Namely, there must be either none or an infinite number of massive spin-2 modes, and the mass ratio between consecutive Kaluza-Klain spin-2 replicas is bounded by the 4d coupling constants.

General relativity (GR) as described in terms of curvature by the Einstein-Hilbert action is dynamically equivalent to theories of gravity formulated in terms of spacetime torsion or nonmetricity. This forms what is called the geometrical trinity of gravity. The theories corresponding to this trinity are, apart from GR, the teleparallel (TEGR) and symmetric teleparallel (STEGR) equivalent theories of general relativity, respectively, and their actions are equivalent to GR up to boundary terms $B$. We investigate how the Gibbons-Hawking-York (GHY) boundary term of GR changes under the transition to TEGR and STEGR within the framework of metric-affine gravity. We show that $B$ is the difference between the GHY term of GR and that of metric-affine gravity. Moreover, we show that the GHY term for both TEGR and STEGR must vanish for consistency of the variational problem. Furthermore, our approach allows to extend the equivalence between GR, TEGR and STEGR beyond the Einstein-Hilbert action to any action built out of the curvature two-form, thus establishing the generalized geometrical trinity of gravity. We argue that these results will be particularly useful in view of studying gauge/gravity duality for theories with torsion and nonmetricity.

Equatorial circular geodesic orbits of neutral test particles in the exterior spacetime of a charged rotating disc of dust are analyzed in dependence of its specific charge and a relativity parameter. The charged rotating disc of dust is an axisymmetric, stationary solution of the Einstein-Maxwell equations in terms of a post-Newtonian expansion. In particular, photon, marginally bound and marginally stable orbits are discussed. It turns out that general formulae in closed form for angular velocity, specific energy and specific angular momentum of the test particles can be derived, which hold for any (exterior) asymptotically flat, axisymmetric, stationary and reflection symmetric (electro-)vacuum spacetime. Furthermore, circular motion in the exterior spacetime of the charged rotating disc of dust is qualitatively very similar to that around a Kerr-Newman black hole for sufficiently large radii, but differs strongly in the respective closer vicinity.

The Euler-Heisenberg theory sheds light on the quantum electrodynamical vacuum corrections to the Maxwell-Lorentz theory. As a fundamental assumption to ensure spacetime causality, by examining the quasinormal modes of a massless neutral scalar field, we investigate the strong cosmic censorship (SCC) conjecture in the context of Euler-Heisenberg-de-Sitter black holes under the massless scalar perturbation. With the emergence of Euler-Heisenberg corrections, Euler-Heisenberg-dS black holes exhibit four horizons and two types of extremal conditions. The first type of extremal conditions, similar to the Reissner-Nordstrom-de Sitter (RNdS) spacetime, involves the coinciding Cauchy and event horizons, while the second type involves the innermost and Cauchy horizons coinciding. Through numerical calculations, we find that SCC is violated not only near the commonly observed first-type extremal solutions but also in the vicinity of second-type extremal black holes. This marks the first instance of SCC violation in another region besides the vicinity of first-type extremal black holes within the classical framework. Additionally, we observe that the validation region of charge ratio shrinks as the reduced Euler-Heisenberg parameter $\alpha /M^2$ increases, and beyond a critical value of $\alpha /M^2$, all black hole solutions violate SCC. These findings suggest a greater likelihood of SCC violation with higher reduced Euler-Heisenberg parameter values. Furthermore, when $\alpha /M^2$ is sufficiently large, not only is the Christodoulou version of SCC violated but also the $C^2$ version. This marks the first instance of $C^2$ version SCC violation found under massless scalar field perturbations. Finally, we extend our research to cases where the scalar field nonminimally couples to electromagnetic invariants and find that, similar to the RNdS case, when the coupling constant b is sufficiently large, the SCC can also be restored in Euler-Heisenberg-dS black holes.

We analyze primordial tensor perturbations using the latest cosmic microwave background and gravitational waves data, focusing on the tensor-to-scalar ratio, $r$, and the tensor spectral tilt, $n_t$. Utilizing data from Planck PR4, BICEP/Keck, and LIGO-Virgo-KAGRA, we employ both Bayesian and frequentist methods to provide robust constraints on these parameters. Our results indicate more conservative upper limits for $r$ with profile likelihoods compared to Bayesian credible intervals, highlighting the influence of prior selection and volume effects. The profile likelihood for $n_t$ shows that the current data do not provide sufficient information to derive quantitative bounds, unless extra assumptions on $r$ are used. Additionally, we conduct a 2D profile likelihood analysis of $r$ and $n_t$, indicating a closer agreement between both statistical methods for the largest values of $r$. This study not only updates our understanding of the tensor perturbations but also highlights the importance of employing both statistical methods to explore less constrained parameters, crucial for future explorations in cosmology.

Standard cosmic microwave background (CMB) analyses constrain cosmological and astrophysical parameters by fitting parametric models to multifrequency power spectra (MFPS). However, such methods do not optimally weight maps in power spectrum (PS) measurements for non-Gaussian cosmic microwave background (CMB) foregrounds. We propose needlet internal linear combination (NILC), operating on wavelets with compact support in pixel and harmonic space, as a weighting scheme to yield more optimal parameter constraints. In a companion paper, we derived an analytic formula for the NILC map PS, which is physically insightful but computationally difficult to use in parameter inference pipelines. In this work, we analytically show that fitting parametric templates to MFPS and the harmonic ILC PS yields identical parameter constraints when the number of sky components equals or exceeds the number of frequency channels. We numerically show that, for Gaussian random fields, the same holds for the NILC PS. This suggests that NILC can reduce parameter error bars in the presence of non-Gaussian fields since it uses non-Gaussian information. As Gaussian likelihoods may be inaccurate, we use likelihood-free inference with neural posterior estimation. We show that performing inference with autospectra and cross-PS of NILC component maps as summary statistics yields smaller parameter error bars than inference with MFPS. For a model with CMB, an amplified thermal Sunyaev-Zel’dovich (tSZ) signal, and noise, we find a 60% reduction in the area of the 2D 68% confidence region for component amplitude parameters inferred from the NILC PS, as compared to inference from MFPS. Primordial $B$-mode searches are a promising application for our new method, as the amplitude of the non-Gaussian dust foreground is known to be larger than a potential signal.

The internal linear combination (ILC) method is a popular approach for constructing component-separated maps in cosmic microwave background analyses. It optimally combines observed maps at different frequencies to produce an unbiased minimum-variance map of a component. When performed in harmonic space, it is straightforward to analytically compute the contributions of individual sky components to the power spectrum of the resulting ILC map. ILC can also be performed on a basis of needlets, spherical wavelets that have compact support in both pixel and harmonic space, capturing both scale-dependent and spatially varying information. However, an analytic understanding of the power spectra of needlet ILC (NILC) component-separated maps, as needed to enable their use in cosmological parameter inference, has remained an outstanding problem. In this paper, we derive the first analytic expression for the power spectra of NILC maps, as well as an expression for the cross spectrum of a NILC map with an arbitrary second map, in terms of contributions from individual sky components. We validate our result using simulations, finding that it is exact. These results contain useful insights: we explicitly see how NILC power spectra contain information from contaminant fields beyond the two-point level, and we obtain a formalism with which to parametrize NILC power spectra. However, because this parameter dependence is complicated by correlations and higher-point functions of the component maps and weight maps, we find that it is intractable to perform parameter inference using these analytic expressions. Instead, numerical techniques are needed to estimate parameters using NILC maps—we explore the use of likelihood-free inference with neural posterior estimation in a companion paper.

A method of general applicability has been developed, whereby the null geodesic equations of the Einstein-Straus–de Sitter metric can be integrated simultaneously in terms of the curvature constant $k$. The purpose is to generalize the computation of light deflection and time delay by a spherical mass distribution. Assuming a flat Universe with most recent measurements of the Hubble constant $H_0$ and the cosmological constant $\mathrm{\Lambda }$, five time delays between the four bright images of the lensed quasar SDSS $\mathrm{J}1004+4112$ have been forecasted and compared to others in the field, $\mathrm{\Delta }{t}_{DC}=(3250\pm 64)\mathrm{days}$ (8.90 yr), $\mathrm{\Delta }{t}_{DA}=2049_{-58}^{+59}\mathrm{days}$ (5.61 yr), $\mathrm{\Delta }{t}_{AC}=(1269\pm 77)\mathrm{days}$ (3.47 yr), $\mathrm{\Delta }{t}_{BC}=1176_{-77}^{+78}\mathrm{days}$ (3.22 yr), and $\mathrm{\Delta }{t}_{AB}=(93\pm 70)\mathrm{days}$. This set of time delays constrains the galaxy cluster mass to be $M=(2.447\pm 0.73)\times {10}^{13}{M}_{\odot }$. In addition, we have reviewed the question of the possible contribution of a positive $\mathrm{\Lambda }$ to reduce the light bending, and concluded that the changes are seemingly too small to be appreciable on cosmological scales. The same conclusion has been reached regarding the time delay. Having addressed the question of the effect of the spatial curvature in both closed and open Universe, we have found that the strong lensing is slightly affected by the expected small curvature density ${\mathrm{\Omega }}_{k0}$ of the current Universe within its error bar $|{\mathrm{\Omega }}_{k0}|⪅0.001$, in such a way that it may safely be neglected. However, it is only if ${\mathrm{\Omega }}_{k0}$ gets quite larger that the effect being noticeable. While it is only theoretically possible for ${\mathrm{\Omega }}_{k0}$ to be higher, it is worthwhile to stress that this should impact the light bending and time delay, causing them to decrease or increase depending upon whether the spatial curvature is positive or negative. Furthermore, one can infer that the observed light deflection and time delay independently, which are found to be significantly deviated from those of the flat Universe, may serve as a useful means to provide constraints on ${\mathrm{\Omega }}_{k0}$, thus making the approach employed in this work more promising than others.

\We report results on the first matched-filtering search for binaries with compact objects having large tidal deformabilities in the LIGO-Virgo gravitational wave (GW) data. The tidal deformability of a body is quantified by the “Love number” $\mathrm{\Lambda }\propto (r/m{)}^5$, where $r/m$ is the body’s (inverse) compactness. Due to its strong dependence on compactness, the $\mathrm{\Lambda }$ of larger-sized compact objects can easily be many orders of magnitude greater than those of black holes and neutron stars, leaving phase shifts which are sufficiently large for these binaries to be missed by binary black hole (BBH) templated searches. In this paper, we conduct a search using inspiral-only waveforms with zero spins but finite tides, with the search space covering chirp masses $3M_{\odot }<\mathcal{M}<15M_{\odot }$ and effective tidal deformabilities ${10}^2\lesssim \tilde{\mathrm{\Lambda }}\lesssim {10}^6$. We find no statistically significant GW candidates. This null detection implies an upper limit on the merger rate of such binaries in the range $[1-300]{\mathrm{Gpc}}^{-3}{\mathrm{year}}^{-1}$, depending on $\mathcal{M}$ and $\tilde{\mathrm{\Lambda }}$. While our constraints are model agnostic, we discuss the implications on beyond the Standard Model scenarios that give rise to boson stars and superradiant clouds. Using inspiral-only waveforms, we recover many of the BBH signals which were previously identified with full inspiral-merger-ringdown templates. We also empirically constrain the Love number of the compact objects in these binaries to $\mathrm{\Lambda }\lesssim {10}^3$ at the 90% credible level in the best cases, consistent with the expectation of vanishing Love number for black holes in general relativity. Our work is the first-ever dedicated template-based search for compact objects that are not black holes or neutron stars. Additionally, our work demonstrates a novel way of finding new physics in GW data, widening the scope of potential discovery to previously unexplored parameter space.

We provide comprehensive calculations of total muon fluxes, energy and angular spectra, and mean muon energies in deep underground laboratories—under flat overburdens and mountains and underwater—using our latest calculation code, mute v3. For precise modeling, we compiled rock densities and chemical compositions for various underground labs, as well as topographic map profiles of overburdens, and integrated them into our calculations. Our results show excellent agreement with available data for most underground sites when using the latest surface muon flux model, daemonflux. Moreover, since our calculations do not rely on underground measurements of muons or other secondaries, we can verify the consistency of measurements across different detectors at different sites. mute is an open-source, publicly available program, providing a solid framework for accurate muon flux predictions in various underground environments, essential for applications in cosmic ray physics and dark matter searches.

With this article, we introduce recent, improved machine learning methods from computer vision to the problem of event classification in particle physics. Supersymmetric scalar top decays to top quarks and weak-scale bino-like neutralinos, where the neutralinos decay via the $UDD$ operator to three quarks, are difficult to search for and therefore weakly constrained. The jet substructure of the boosted decay products can be used to differentiate signal from background events. We apply the transformer-based computer vision models coatnet and maxvit to images built from jet constituents and compare the classification performance to a more classical convolutional neural network (CNN). We find that results from computer vision translate well to physics applications, and both transformer-based models perform better than the CNN. By replacing the CNN with maxvit, we find an improvement of $S/\sqrt{B}$ by a factor of almost 2 for some neutralino masses. We show that combining this classifier with additional features results in a strong separation of background and signal. We also find that replacing a CNN with a maxvit model in a simple mock analysis can push the 95% C.L. exclusion limit of stop masses by about 100 and 60 GeV for neutralino masses of 100 and 500 GeV.

We study the existence of Bogomol’nyi-Prasad-Sommerfield (BPS) configurations in a restricted baby Skyrme-Maxwell enlarged via the inclusion of a nontrivial magnetic permeability. In order to attain such a goal, we use the BPS prescription, which allows us to obtain the lower bound for the energy and the BPS equations whose (electrically neutral) solutions saturate that bound. During the energy minimization procedure, we find a differential constraint which involves the self-dual potential, the superpotential itself, and also the magnetic permeability. In order to solve the BPS system, we focus our attention on those solutions with rotational symmetry. For that, we fix the magnetic permeability and select two BPS potentials which exhibit a similar behavior near to the vacuum. We depict the resulting profiles and proceed to an analytical description of the properties of the BPS magnetic field. Furthermore, we consider some essential aspects of our model, such as the conditions for the overall existence of the BPS solutions, and how the permeability affects the magnetic flux. Finally, we present a family of exact BPS solutions.