The large-scale analysis task of deciphering gravitational-wave signals in the LISA data stream will be difficult, requiring a large amount of computational resources and extensive development of computational methods. Its high dimensionality, multiple model types, and complicated noise profile require a global fit to all parameters and input models simultaneously. In this work, we detail our global fit algorithm, called “Erebor,” designed to accomplish this challenging task. It is capable of analyzing current state-of-the-art datasets and then growing into the future as more pieces of the pipeline are completed and added. We describe our pipeline strategy, the algorithmic setup, and the results from our analysis of the LDC2A Sangria dataset, which contains massive black hole binaries, compact galactic binaries, and a parametrized noise spectrum whose parameters are unknown to the user. The Erebor algorithm includes three unique and very useful contributions: GPU acceleration for enhanced computational efficiency; ensemble Markov Chain Monte Carlo (MCMC) sampling with multiple MCMC walkers per temperature for better mixing and parallelized sample creation; and special online updates to reversible-jump (or transdimensional) sampling distributions to ensure sampler mixing and accurate initial estimates for detectable sources in the data. We recover posterior distributions for all 15 (6) of the injected massive black hole binaries (MBHB) in the LDC2A training (hidden) dataset. We catalog $\sim 12000$ galactic binaries ($\sim 8000$ as high confidence detections) for both the training and hidden datasets. All of the sources and their posterior distributions are provided in publicly available catalogs.

Wave or fuzzy dark matter that is produced with relativistic wave numbers exhibits free-streaming effects analogous to warm or hot particle dark matter with relativistic momenta. Axions produced after inflation provide such a warm or mildly relativistic candidate, where the enhanced suppression and observational bounds are only moderately stronger than that from wave propagation of initially cold axions. More generally, the free-streaming damping also impacts isocurvature fluctuations from generation in causally disconnected patches. As coherent spatial fluctuations free stream away they leave incoherent and transient superpositions in their wakes. These multiple wave momentum streams are the wave analog of particle phase space fluctuations or directional collisionless damping of massive neutrinos or hot dark matter. The observable impact on both adiabatic and isocurvature fluctuations of fuzzy dark matter can differ from their cold dark matter counterparts due to free streaming depending on how warm or hot is their momentum distribution.

In this work, we leverage cosmic microwave background (CMB) data from the Atacama Cosmology Telescope (ACT) and LSS data from the imaging survey conducted by the Dark Energy Spectroscopic Instrument (DESI) to study the distribution of gas around galaxy groups at low redshift, $z\approx 0.3$, via the kinematic Sunyaev-Zel’dovich (kSZ) effect. In particular, we perform velocity-weighted stacking on the photometric galaxies from the Bright Galaxy Survey (BGS) to isolate the monopole and quadrupole of the kSZ signal, orienting the stacked images along 2D filaments identified using the Hessian of the projected gravitational potential. We find a $7.2\sigma$ detection in the monopole of the signal (i.e., the gas density profile) and a $4\sigma$ detection in the quadrupole ($m=2$), constituting the first measurement of the alignment between gas distribution and the cosmic web through the kSZ effect. As it is a linear probe of the local gas density, the kSZ has heightened sensitivity to the warm-hot intergalactic medium (WHIM), which is believed to house the majority of the “missing baryons.” Mapping out the gas density at low redshifts, as enabled by our measurements, is crucial for weak lensing surveys, for which the impact of baryons on small scales is a major impediment. We compare the anisotropic signal against two hydrodynamical simulations, TNG300-1 and Illustris, which have very different baryonic feedback prescriptions. We find that the anisotropic signal measured in the data is comparable but slightly larger and more extended compared with the simulations. This suggests that there is excess accretion and feedback taking place through the filaments, hinting at the possible presence of spin-filament alignment of the BGS objects.

The recent detection of gravitational waves (GWs) by pulsar timing array (PTA) collaborations spurred a variety of questions regarding the origin of the signal and the properties of its sources. The amplitude of a GW background produced by inspiralling supermassive black holes (SMBHs) can be predicted in a relatively robust manner from the present-day merged remnants, observed as single SMBHs at the centers of galaxies, but falls short of the signal measured by PTAs by a significant amount, requiring equal mass mergers, extremely short delay times, and no accretion in order to achieve a modest consistency. In this work, we revisit NANOGrav’s 15-yr dataset and reassess the aforementioned discrepancy using the full spectral information captured by PTA data. As previously noted in the literature, the discrete number of point sources contributing to the background may lead to deviations in the observed spectrum relative to the average ($h_c^2\propto f^{-4/3}$) due to Poisson fluctuations, providing additional information about the source population beyond the background amplitude. We derive a simple expression for the characteristic strain distribution given a SMBH model, which is generally applicable regardless of the method used to model the black hole population. We then refit the NANOGrav free spectrum using a minimal model based on the local mass function, showing that the current GW measurement requires roughly $\sim 10$ times more black holes than suggested by local observations and disfavors mass functions dominated by few very heavy sources, with the typical mass that contributes to the background $\lesssim {10}^{10}{M}_{\odot }$. Given the range of SMBH models found to be consistent with the isotropic background, we address what is the typical number sources that would be individually detectable, given the current sensitivity.

We investigate the impact of preheating on baryogenesis in $R^2$-Higgs inflation. In this scenario, the inclusion of a dimension-six operator $(R/{\mathrm{\Lambda }}^2)B_{\mu \nu }{\tilde{B}}^{\mu \nu }$ abundantly generates helical hypermagnetic fields during inflation, leading to a baryon asymmetric Universe at the electroweak crossover. Focusing on the $R^2$-like regime, we first derive the relevant dynamics of preheating using a doubly covariant formalism. We find that preheating can happen for the Higgs, transverse gauge, and Goldstone bosons, however, it is dependent on the value of the nonminimal coupling ${\xi }_H$ between the Standard Model Higgs field and the Ricci scalar. We identify the preheating temperature to determine the appropriate scale $\mathrm{\Lambda }$ for driving baryogenesis, which is around $\mathrm{\Lambda }\sim 2.2(2.6)\times {10}^{-5}{M}_{\mathrm{P}}$ for ${\xi }_H\sim 1(10)$. Our results represent the most accurate estimation of the scale of gravity induced baryogenesis in $R^2$-Higgs inflation to date. Areas for further improvement are identified.

Dark matter may exist today in the form of ultraheavy composite bound states. Collisions between such dark matter states can release intense bursts of radiation that include $\gamma$-rays among the final products. Thus, indirect detection signals of dark matter may include unconventional $\gamma$-ray bursts. Such bursts may have been missed not necessarily because of their low arriving $\gamma$-ray fluxes, but rather their briefness and rareness. We point out that intense bursts whose nondetection thus far are due to the latter can be detected in the near future with existing and planned facilities. In particular, we propose that, with slight experimental adjustments and suitable data analyses, imaging atmospheric Cherenkov telescopes (IACTs) and Pulsed All-Sky Near-Infrared and Optical Search for Extra-Terrestrial Intelligence (PANOSETI) are promising tools for detecting such rare, brief, but intense bursts. We also show that, if we assume these bursts originate from collisions of dark matter states, IACTs and PANOSETI can probe a large dark matter parameter space beyond existing limits. Additionally, we present a concrete model of dark matter that produces bursts potentially detectable in these instruments.

Recent evidence of a stochastic gravitational wave (GW) background found by NANOGrav and other pulsar timing array (PTA) collaborations has inspired many studies looking for possible sources. We consider the hypothesis that the GW signature is produced by domain walls (DWs) arising in the doublet left-right symmetric model (DLRSM) due to the spontaneous breaking of the discrete parity symmetry. We show that the DW network consists of two types of DWs, namely $Z_2$ and $LR$ DWs, and solve the kink equations to obtain the parametric dependence of the surface tension in the two cases. We argue that the $Z_2$ DWs are unstable due to higher surface tension, leading to a stable network consisting only of $LR$ DWs. Considering the GW signal from the DLRSM DW model with and without the contribution from supermassive black hole binaries, we perform a Bayesian analysis using the PTA data to estimate the posterior distribution and identify best-fit parameter ranges. The PTA data favors a parity-breaking scale of $\mathcal{O}({10}^5)\mathrm{GeV}$, and a biased potential $V_{\mathrm{bias}}\sim (\mathcal{O}(100)\mathrm{MeV}{)}^4$. The model with only DLRSM DWs is slightly favored over the model where additional supermassive black hole binaries contribution is considered.

We study potential contribution of the heavy right-handed neutrino exchange in the process $e^{+}{e}^{-}\to W^{+}{W}^{-}$. This process is sensitive to heavy neutrinos with masses larger than $\sqrt{s}$. The Monte Carlo simulation of the studied process is performed assuming the seesaw type-I model, where heavy right-handed neutrinos (heavy neutral leptons, HNLs) are introduced in the leptonic sector. Within the Standard Model (SM), the process has a large cross section described by diagrams with $s$-channel $Z/\gamma$ exchange and $t$-channel active neutrino exchange. Respectively, the $t$-channel right-handed neutrino exchange amplitude will interfere with these SM amplitudes. However, the angular distributions of the $W$ boson production and decay are different for the right-handed neutrino and SM amplitudes. That can be used to evaluate potential HNL contribution using the extended likelihood method. The simulation of the $e^{+}{e}^{-}\to W^{+}{W}^{-}$ process is performed at the 1 TeV center-of-mass energy and polarization ${\mathcal{P}}_{e^{+}{e}^{-}}$ of (20%, $-80\%$), which is a standard option for the future linear $e^{+}{e}^{-}$ International Linear Collider. Both $W$ bosons are reconstructed from two hadronic jets. Simulation of the SM background processes is also done. The beam-induced backgrounds and the initial state radiation effects are taken into account. The majority of background processes are effectively suppressed by the cuts on the invariant masses of two and four jets. Finally, we obtain upper limits on the mixing parameter $|V_{eN}{|}^2$ as a function of $M(N)$.

We reexamine a dynamical dark matter model with Kaluza-Klein (KK) towers of gravitons and neutrinos fitting together in the dark dimension. We show that even though gravitational decays of neutrino KK towers have little impact in cosmology, the weak decay channel could have significant cosmological effects. Taking conservative upper bounds on the dark matter decay rate into two photons before reionization and on the number of effective extra neutrino species $\mathrm{\Delta }{N}_{\mathrm{eff}}$, we derive constraints on the conversion rate from active to sterile species despite the dependence of the mixing angle on the KK mode mass. We also provide counterarguments to a recent claim suggesting that the bounds on $\mathrm{\Delta }{N}_{\mathrm{eff}}$ rule out micron-sized extra dimensions.

We explore the production and possible detection of a charged scalar Higgs pair $H^{-}{H}^{+}$ decaying into the final state $\mu {\nu }_{\mu }cb$ in proton-proton collisions at the LHC and its next step, the high luminosity LHC (HL-LHC). The charged scalars are predicted within the theoretical framework of the two-Higgs doublet model of type III (2HDM-III). As a test and validation of the model, we identify regions of the 2HDM-III parameter space that accommodate the current excess of events at $3\sigma$ in the process $\mathcal{B}\mathcal{R}(t\to H^{\pm }b)\times \mathcal{B}\mathcal{R}(H^{\pm }\to cb)$ for $M_{H^{\pm }}=130\mathrm{GeV}$, as reported by ATLAS Collaboration. Theoretical and additional experimental constraints are also included. Based on this, we propose realistic scenarios that could be brought under experimental scrutiny at the HL-LHC. Assuming the most favorable scenario, we predict a signal significance at the level of $5\sigma$ for a charged scalar boson mass $M_{H^{\pm }}$ in the 100–350 GeV range.

We reexamine by numerical simulation the phase structure of the three-dimensional Abelian lattice gauge theory with $Z(2)$ gauge fields coupled to $Z(2)$-valued Higgs fields. Concretely, we explore two different order parameters which are able to distinguish the three phases of the theory: (i) the Fredenhagen-Marcu operator used to discriminate between deconfinement and confinement/Higgs phases and (ii) the Greensite-Matsuyama overlap operator proposed recently to distinguish confinement and Higgs phases. The latter operator is an analog of the overlap Edwards-Anderson order parameter for spin glasses. According to it, the Higgs phase is realized as a glassy phase of the gauge system. For this reason standard tricks for simulations of spin-glass phases are utilized in this work, namely tempered Monte Carlo and averaging over replicas. In addition, we also present results for a certain definition of distance between Higgs field configurations. Finally, we calculate various gauge-invariant correlation functions in order to extract the corresponding masses.

The spin correlations in the pair of $\tau$ leptons produced in high-energy proton-proton collisions are studied. The invariant mass of the $\tau$-lepton pair is chosen close to the $Z$-boson mass; in these conditions, $Z$-boson exchange gives the dominant contribution to the Drell-Yan mechanism. The interaction of $Z$ bosons with $\tau$ leptons, in addition to the Standard Model couplings, can include weak anomalous magnetic and electric dipole moments (or form factors) of the $\tau$ lepton. The dependence of elements of the $pp$ spin-correlation matrix on the weak anomalous moments is determined for various regions of the rapidity of the $\tau$-lepton pair. Based on this calculation, we construct a semirealistic observable built on the momenta of pions in the ${\tau }^{\mp }\to {\pi }^{\mp }{\nu }_{\tau }$ and ${\tau }^{\pm }\to {\rho }^{\pm }{\nu }_{\tau }\to {\pi }^{\pm }{\pi }^0{\nu }_{\tau }$ decay channels, and we show that this observable can be sensitive to the weak anomalous dipole moments.

This paper reports the first measurement of the transverse momentum ($p_{\mathrm{T}}$) spectra of primary charged pions, kaons, (anti)protons, and unidentified particles as a function of the charged-particle flattenicity in pp collisions at $\sqrt{s}=13\mathrm{TeV}$. Flattenicity is a novel event shape observable that is measured in the pseudorapidity intervals covered by the V0 detector, $2.8<\eta <5.1$ and $-3.7<\eta <-1.7$. According to QCD-inspired phenomenological models, it shows sensitivity to multiparton interactions and is less affected by biases toward larger $p_{\mathrm{T}}$ due to local multiplicity fluctuations in the V0 acceptance than multiplicity. The analysis is performed in minimum-bias (MB) as well as in high-multiplicity events up to $p_{\mathrm{T}}=20\mathrm{GeV}/c$. The event selection requires at least one charged particle produced in the pseudorapidity interval $|\eta |<1$. The measured $p_{\mathrm{T}}$ distributions, average $p_{\mathrm{T}}$, kaon-to-pion and proton-to-pion particle ratios, presented in this paper, are compared to model calculations using pythia 8 based on color strings and EPOS LHC. The modification of the $p_{\mathrm{T}}$-spectral shapes in low-flattenicity events that have large event activity with respect to those measured in MB events develops a pronounced peak at intermediate $p_{\mathrm{T}}$ ($2<p_{\mathrm{T}}<8\mathrm{GeV}/c$), and approaches the vicinity of unity at higher $p_{\mathrm{T}}$. The results are qualitatively described by pythia, and they show different behavior than those measured as a function of charged-particle multiplicity based on the V0M estimator.

A search is performed for charged-lepton flavor violating processes in top quark ($t$) production and decay. The data were collected by the CMS experiment from proton-proton collisions at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of $138{\mathrm{fb}}^{-1}$. The selected events are required to contain one opposite-sign electron-muon pair, a third charged lepton (electron or muon), and at least one jet of which no more than one is associated with a bottom quark. Boosted decision trees are used to distinguish signal from background, exploiting differences in the kinematics of the final states particles. The data are consistent with the standard model expectation. Upper limits at 95% confidence level are placed in the context of effective field theory on the Wilson coefficients, which range between $0.024–0.424{\mathrm{TeV}}^{-2}$ depending on the flavor of the associated light quark and the Lorentz structure of the interaction. These limits are converted to upper limits on branching fractions involving up (charm) quarks, $t\to e\mu u$ ($t\to e\mu c$), of $0.032(0.498)\times {10}^{-6}$, $0.022(0.369)\times {10}^{-6}$, and $0.012(0.216)\times {10}^{-6}$ for tensorlike, vectorlike, and scalarlike interactions, respectively.

In conformal field theories, in contrast to adding some auxiliary states into the bipartite mixed state ${\rho }_{AB}$ as the usual purifications do, we show a pure entangled state ${\psi }_{AB}$ can be constructed by subtracting the undetectable regions. In this pure state ${\psi }_{AB}$, the von Neumann entropy $S_{\mathrm{vN}}(A:B)$ naturally captures quantum entanglement between $A$ and $B$. We verify that $S_{\mathrm{vN}}(A:B)$ is equal to the entanglement wedge cross section $E_W$ in anti–de Sitter spacetime, which is conjectured to be the holographic dual of the entanglement of purification.

Within the framework of nonrelativistic QCD (NRQCD) effective field theory, we study the leptoproduction of $J/\psi$ at next-to-leading order in perturbative QCD for both unpolarized and polarized electron-ion collisions. We demonstrate that the $J/\psi$-tagged deep inelastic scattering in the future Electron-Ion Collider can be served as a golden channel for reasons including constraining NRQCD long-distance matrix elements, probing the nuclear gluon distribution functions, as well as investigating the gluon helicity distribution inside a longitudinal polarized proton.

M-theory frozen singularities are (locally) $D$- or $E$-type orbifold singularities with a background fractional $C_3$-monodromy surrounding them. In this paper, we revisit such backgrounds and address several puzzling features of their physics. We first give a top-down derivation of how the $D$- or $E$-type 7D $\mathcal{N}=1$ gauge theory directly “freezes” to a lower-rank gauge theory due to the $C_3$ background. This relies on a Hanany-Witten effect of fractional M5 branes and the presence of a gauge anomaly of fractional $\mathrm{D}p$ probes in the circle reduction. Additionally, we compute defect groups and 8D symmetry topological field theories of the 7D frozen theories in several duality frames. We apply our results to understanding the evenness condition of strings ending on $\mathrm{O}{7}^{+}$ planes, and calculating the global forms of supergravity gauge groups of M-theory compactified on $T^4/\mathrm{\Gamma }$ with frozen singularities. We also revisit IIA $ADE$ singularities with a $C_1$-monodromy along a 1-cycle in the boundary lens space and show that this freezes the gauge degrees of freedom via confinement.

We present a local framework for investigating nonunitary evolution groups pertinent to effective field theories in general semiclassical spacetimes. Our approach is based on a rigorous local stability analysis of the algebra of observables and solely employs geometric concepts in the functional representation of quantum field theory. In this representation, it is possible to construct infinitely many self-adjoint extensions of the canonical momentum field at the kinematic level, and by the usual functional calculus arguments this holds for the Hamiltonian, as well. However, these self-adjoint domains have only the trivial wave functional in common with the solution space of the functional Schrödinger equation. This is related to the existence of boundaries in configuration field space which can be penetrated by the probability flux, causing probability to leak into regions in configuration field space that require a more fundamental description. As a consequence the evolution admits no unitary representation. Instead, in the absence of ghosts, the evolution is represented by contractive semigroups in the semiclassical approximation. This allows us to quantify the unitarity loss and, in turn, to assess the quality of the semiclassical approximation. We perform numerical experiments based on our formal investigations to determine regions in cosmological spacetimes where the semiclassical approximation breaks down for free quantum fields.

We construct, for spin 0,1,2 tensor fields on ${\mathrm{S}}^d$, a set of ladder operators that connect the distinct unitary irreducible representations (UIRs) of $\mathrm{SO}(d+1)$. This is achieved by relying on the conformal Killing vectors of ${\mathrm{S}}^d$. For the case of spinning fields, the ladder operators generalize previous expressions with a compensating transformation necessary to preserve the transversality condition. We then extend the results to the exceptional/discrete UIRs of $\mathrm{SO}(d,1)$, again relying on the conformal Killing vectors of de Sitter space. Our construction recovers the conventional conformal primary transformations for the scalar fields when the mass term leads to conformal coupling. A similar approach for the spin-2 field leads to the conformal-like operators found recently.