There is a growing need for machine-learning-based anomaly detection strategies to broaden the search for beyond-the-Standard-Model physics at the Large Hadron Collider (LHC) and elsewhere. The first step of any anomaly detection approach is to specify observables and then use them to decide on a set of anomalous events. One common choice is to select events that have low probability density. It is a well-known fact that probability densities are not invariant under coordinate transformations, so the sensitivity can depend on the initial choice of coordinates. The broader machine learning community has recently connected coordinate sensitivity with anomaly detection and our goal is to bring awareness of this issue to the growing high-energy physics literature on anomaly detection. In addition to analytical explanations, we provide numerical examples from simple random variables and from the LHC Olympics dataset that show how using probability density as an anomaly score can lead to events being classified as anomalous or not depending on the coordinate frame.

In this paper, we analyze the holographic covariant entanglement entropy in the double Wick rotated version of a rotating Banados-Teitelboim-Zanelli black hole (3-dimensional Kerr-AdS solution), where the periodicity of Euclidean time and spatial direction are changed. The dual field theory has negative energy in the Lorentzian signature. The holographic entanglement entropy agrees with its conformal field theory counterpart, which is obtained by a conformal transformation of the correlation functions of twisted operators.

We revisit the mechanism of vortex unpinning caused by the neutron-vortex scattering [B. Layek and P. R. Yadav, Mon. Not. R. Astron. Soc. 499, 455 (2020)] in the inner crust of a pulsar. The strain energy released by the crustquake is assumed to be absorbed in some part of the inner crust and causes pair-breaking quasineutron excitations from the existing free neutron superfluid in the bulk of the inner crust. The scattering of these quasineutrons with the vortex core normal neutrons unpins a large number of vortices from the thermally affected regions and results in pulsar glitches. We consider the geometry of a cylindrical shell of the affected pinning region to study the implications of the vortex unpinning in the context of pulsar glitches. We find that a pulsar can release about $\sim {10}^{11}–{10}^{13}$ vortices by this mechanism. These numbers are equivalent to the glitch size of orders $\sim {10}^{-11}–{10}^{-9}$ for Vela-like pulsars with the characteristic age $\tau \simeq {10}^4\mathrm{years}$. We also suggest a possibility of a vortex avalanche triggered by the movement of the unpinned vortices. A rough estimate of the glitch size caused by an avalanche shows an encouraging result.

Fundamental constants such as masses and coupling constants of elementary particles can have small temporal and spatial variations in the scalar field dark-matter model. These variations entail time oscillations of other constants, such as the Bohr and nuclear magnetons, Bohr radius, and the hyperfine structure constant. In the presence of an external magnetic field, these oscillations induce hyperfine transitions in atoms and molecules. We determine the probability of magnetic dipole hyperfine transitions, caused by the oscillating fundamental constants, and propose an experiment that could detect the scalar field dark matter through this effect. This experiment may be sensitive to the scalar field and axion dark matter with mass in the range $1\mathit{\mu }\mathrm{eV}<m<100\mathit{\mu }\mathrm{eV}$.

The phenomenology of axions and axionlike particles strongly depends on their couplings to Standard Model particles. The focus of this paper is the phenomenology of the unique dimension-six operator respecting the shift symmetry: the axion-Higgs portal. We compare constraints from Higgs physics, flavor-violating and radiative meson decays, bounds from atomic spectroscopy searching for fifth forces, and astrophysical observables. In contrast to the QCD axion, axions interacting through the axion-Higgs portal are stable and can provide a dark matter candidate for any axion mass. We derive the parameter space for which freeze-out and freeze-in production, as well as the misalignment mechanism, can reproduce the observed relic abundance and compare the results with the phenomenological constraints. For comparison, we also derive Higgs, flavor, and spectroscopy constraints, and the parameter space for which the scalar Higgs portal without derivative interactions can explain dark matter.

We present a singly charged scalar extension of the scotogenic model, the scotogenic-Zee model, which resolves the recently reported deviations in the $W$ boson mass as well as lepton $g-2$. The model admits a scalar or a fermionic dark matter while realizing naturally small radiative neutrino masses. The mass splitting of $\sim 100\mathrm{GeV}$, which is required by the shift in $W$ boson mass, among the inert doublet fields can be evaded by its mixing with the singlet scalar, which is also key to resolving the $(g-2{)}_{\ell }$ anomaly within $1\sigma$. We establish the consistency of this framework with dark matter relic abundance while satisfying constraints from charged lepton flavor violation, direct detection, and collider bounds. The model gives predictions for the lepton flavor violating $\tau \to \ell \gamma$ processes that will be testable in upcoming experiments.

We use three-flavor chiral perturbation theory ($\chi \mathrm{PT}$) to calculate the pressure, light, and $s$-quark condensates of QCD in the confined phase at finite temperature to $\mathcal{O}(p^6)$ in the low-energy expansion. We also include electromagnetic effects to order $e^2$, where the electromagnetic coupling $e$ counts as order $p$. Our results for the pressure and the condensates suggest that $\chi \mathrm{PT}$ converges very well for temperatures up to approximately 150 MeV. We combine $\chi \mathrm{PT}$ and the hadron resonance gas (HRG) model by adding heavier baryons and mesons. Our results are compared with lattice simulations and the agreement is very good for temperatures below 170 MeV, in contrast to the results from $\chi \mathrm{PT}$ which agree with the lattice only up to $T\approx 120\mathrm{MeV}$. Our value for the chiral crossover temperature is 160.1 MeV, which compares favorably to the lattice result of 157.3 MeV.

We study the power corrections for electroweak boson production that are implied by threshold resummation, which we have extended to massive particles produced at measured transverse momentum, $p_T$, and rapidity. Power corrections in the resulting expressions arise from ambiguities in the low-scale behavior of the perturbative running coupling. Arguing for the relevance of the eikonal approximation, we show that such power corrections begin at order $1/p_T^2$ in full QCD, consistent with fixed-order, massive-gluon analysis. For large-$N$ Mellin moments, the leading behavior is $N^2/p_T^2$, which exponentiates along with the logarithms of threshold resummation.

Within the framework of NRQCD, we calculate the production of the excited doubly heavy baryons ${\mathrm{\Xi }}_{bQ}$ through the semi-inclusive production process $t\to ⟨bQ⟩[n]\to {\mathrm{\Xi }}_{bQ}+\overline{Q}+W^{+}$, where $Q=b$ or $c$ quark. The intermediate diquark state $⟨bQ⟩[n]$ is in the excited P-wave state, including ${[}^1{P}_1]$ and ${[}^3{P}_J]$ ($J=0,1,or2$) in both color anitriplet state $\overline{\mathbf{3}}$ and color sixtuplet state $\mathbf{6}$; that is, $⟨bc⟩{[}^1{P}_1{]}_{\overline{\mathbf{3}}/\mathbf{6}}$, $⟨bc⟩{[}^3{P}_J{]}_{\overline{\mathbf{3}}/\mathbf{6}}$, $⟨bb⟩{[}^1{P}_1{]}_{\overline{\mathbf{3}}}$, and $⟨bb⟩{[}^3{P}_J{]}_{\mathbf{6}}$. We find that the contributions from the P-wave states are about one order lower than the S-wave contributions, and this conclusion is consistent with others. We also analyze the invariant mass and angle differential distributions, and the theoretical uncertainty from the mass parameters, the transition probability, and the renormalization scale. Finally, we can expect that about $1.14\times {10}^{3–5}$ events of excited ${\mathrm{\Xi }}_{bc}$ and $2.47\times {10}^{1–3}$ events of excited ${\mathrm{\Xi }}_{bb}$ can be produced per year at the LHC with $\mathcal{L}={10}^{34–36}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$.

We study the conditions under which the Majorana phase of the two flavor neutrino mixing matrix appears in the oscillation probabilities and causes $CP$ violation. We find that the Majorana phase remains in the neutrino evolution equation if the neutrino decay eigenstates are not aligned with the mass eigenstates. We show that, in general, two kinds of $CP$ violation are possible: one due to the Majorana phase and the other due to the phase of the off-diagonal element of the neutrino decay matrix. We find that the $CP$ violating terms in the oscillation probabilities are also sensitive to neutrino mass ordering.

In a holographic superfluid disk, when the rotational velocity is large enough, we find that a giant vortex will form in the center of the system by merging several single charged vortices at some specific rotational velocity with a phase stratification phenomenon for the order parameter. The formation of a giant vortex can be explained, as there is not enough space for a standard vortex lattice. If we keep increasing the rotational velocity, the giant vortex will disappear and there will be an appearance of a superfluid ring. In the giant vortex region, the number of vortices measured from winding number and rotational velocity always satisfies the linear Feynman relation. However, when the superfluid ring starts to appear, the number of vortices in the disk will decrease although the rotational velocity is increasing, while most of the order parameter is suppressed.

We reconsider $D\ge 4$ dimensional asymptotically flat eternal Schwarzschild black hole and focus on the situation where the inner boundary of the radiation region is chosen to be near the horizon (i.e., $\beta \ll 1$). The tension between the near-horizon condition and the short-distance approximation emerges in large dimensions in [K. Hashimoto, N. Iizuka, and Y. Matsuo, J. High Energy Phys. 06 (2020) 085]. We remove this tension by introducing a more proper near horizon condition; thus, the resulting island solution is well-behaved in any $D\ge 4$ dimensional spacetime. Interestingly, a novel constraint is obtained in this situation as required by the existence of the island solution, which directly leads to the constraints on the size of the Schwarzschild black hole, the position of the inner boundary for the radiation region, or the value of $c·{\tilde{G}}_N$ in any $D\ge 4$ dimension. When considering the large $D$ limit, the constraint on the size of the Schwarzschild black hole obtained in this situation is in agreement with the result given in [F. Holdt-Sordrensen, D. A. McGady, and N. Wintergerst, Phys. Rev. D 102, 026016 (2020)]. We interpret these as the unitary constraints implied by the presence of island in semiclassical gravity.

In time-independent quantum systems, entanglement entropy possesses an inherent scaling symmetry that the energy of the system does not have. The symmetry also assures that entropy divergence can be associated with the zero modes. We generalize this symmetry to time-dependent systems all the way from a coupled harmonic oscillator with a time-dependent frequency, to quantum scalar fields with time-dependent mass. We show that such systems have dynamical scaling symmetry that leaves the evolution of various measures of quantum correlations invariant; entanglement entropy, GS fidelity, the Loschmidt echo, and circuit complexity. Using this symmetry, we show that several quantum correlations are related at late times when the system develops instabilities. We then quantify such instabilities in terms of scrambling time and Lyapunov exponents. The delayed onset of exponential decay of the Loschmidt echo is found to be determined by the largest inverted mode in the system. On the other hand, a zero mode retains information about the system for a considerably longer time, finally resulting in a power-law decay of the Loschmidt echo. We extend the analysis to time-dependent massive scalar fields in ($1+1$)-dimensions and discuss the implications of zero modes and inverted modes occurring in the system at late times. We explicitly show the entropy scaling oscillates between the area-law and volume-law for a scalar field with stable modes or zero modes. We then provide a qualitative discussion of the above effects for scalar fields in cosmological and black hole spacetimes.

A feature shared by many regular black hole spacetimes is the occurrence of a Cauchy horizon. It is then commonly believed that this renders the geometry unstable against perturbations through the mass-inflation effect. In this work, we perform the first dynamical study of this effect taking into account the mass-loss of the black hole due to Hawking radiation. It is shown that the time-dependence of the background leads to two novel types of late-time behavior whose properties are entirely determined by the Hawking flux. The first class of attractor-behavior is operative for regular black holes of the Hayward and renormalization group improved type and characterized by the square of the Weyl curvature growing as $v^6$ at asymptotically late times. This singularity is inaccessible to a radially free-falling observer though. The second class is realized by Reissner-Nordström black holes and regular black holes of the Bardeen type. In this case the curvature scalars remain finite as $v\to \infty$. Thus the Hawking flux has a profound effect on the mass-inflation instability, either weakening the effect significantly or even expelling it entirely.

The semiclassical gravity sourced by the quantum expectation value of the matter’s energy-momentum tensor will change the evolution of the quantum state of matter, which can be described by the Schrödinger-Newton (SN) equation. Understanding the phenomenology of the SN equation is important for experimentally testing the quantumness of gravity. In the SN theory, semiclassical gravity contributes a gravitational potential term depending on the matter’s quantum state. This state-dependent potential introduces the complexity of the quantum state evolution and measurement in SN theory, which is different for different quantum measurement prescriptions. Previous theoretical investigations on the SN-theory phenomenology in the optomechanical experimental platform were carried out under the so-called post/preselection prescription. This work will focus on the phenomenology of SN theory under the causal-conditional prescription, which fits the standard intuition of the continuous quantum measurement process. We found that under the causal-conditional prescription, the quantum state of the test mass mirrors is conditionally prepared by the continuous projection of the outgoing light field in an optomechanical system. Hence a quantum-trajectory-dependent gravitational potential is created, which significantly changes the system evolution. This work provides an extensive analysis of this new picture of system evolution, and shows that various experimentally measurable signatures predicted by SN theory under causal-conditional prescription cannot be distinguished from that predicted by quantum gravity unless a very extreme experimental parameter region is assumed. Therefore, our new understanding of SN phenomenology provides an important caution toward the experimental verification of quantum gravity.

We investigate the reach of the LIGO/Virgo/KAGRA detectors in the search for signatures of first-order phase transitions in the early Universe. Utilizing data from the first three observing runs, we derive constraints on the parameters of the underlying gravitational-wave background, focusing on transitions characterized by strong supercooling. As an application of our analysis, we determine bounds on the parameter space of two representative particle physics models. We also comment on the expected reach of third-generation detectors in probing supercooled phase transitions.

Planck’s cosmic microwave background temperature and polarization observations are the premier dataset for constraining cosmological models. Cosmic variance limited temperature at large and intermediate scales today dominates the constraints; polarization provides additional constraining power and further scrutiny of the models. To complete this picture from Planck, ground-based experiments, such as the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT) continue to add temperature and polarization measurements at small scales, allowing for the extraction of competitive cosmological constraints from the $TE$ and $EE$ power spectra. Matching at the same time all these stringent probes is a key challenge and validation step for any cosmological model. In particular, $\mathrm{\Lambda }\mathrm{CDM}$ requires a tight consistency between the temperature and polarization measurements. In this paper, we present a number of methods to identify and quantify possible inconsistencies between temperature and polarization, we apply them to the latest Planck, ACT, and SPT data and find no evidence for a deviation from $\mathrm{\Lambda }\mathrm{CDM}$. Application of these methods will have increased importance for future, more constraining CMB data.

We explore the possible application of linear covariance-based (LCB) filtering to line-intensity mapping (LIM) signal reconstructions. Originally introduced for reconstruction of the integrated Sachs-Wolfe effect in the cosmic microwave background, the LCB filter is an optimal map estimator that extends the simple Wiener filter by leveraging external correlated data. Given a detectable strong LIM-galaxy or LIM-LIM cross power spectrum, we show recovery of high-redshift, large-scale line-intensity fluctuations—even in the presence of bright interloper emission—in simulations of a futuristic [C ii] LIM survey as well as simulated future iterations of the CO Mapping Array Project. With sufficient galaxy abundances or low LIM survey noise, normalized cross-correlation between the LCB reconstruction and the true signal reaches 70%–90% on large, linear comoving scales corresponding to $k\sim 0.1{\mathrm{Mpc}}^{-1}$. This suggests the possible use of such signal reconstructions in astrophysical or cosmological contexts that require identifying the locations of line emissivity peaks and voids, although clear shortcomings exist on smaller scales. The successful application of the LCB filter in simulated LIM contexts highlights the importance of cross-correlations to studies of the reionizing and reionized high-redshift universe with LIM and other large-scale structure surveys.