Recently, we introduced a symmetry on the structure of angular momentum that interchanges internal and external degrees of freedom. The spin-orbit duality is a holographic map that projects a massive theory in four-dimensional flat spacetime onto the three-dimensional ${\mathbb{S}}^2\times \mathbb{R}$ null infinity. This cylinder has radius $R\sim 1/m$ and, quantum mechanically, its vacuum state is a fuzzy sphere. Progress shows that, first, this duality realizes the Hopf map, a fact manifest on the superparticle. Second, the bulk Poincarè group transforms into the conformal group on the cylinder. In fact, the general version of the duality yields that the dual symmetries include the Bondi-Metzner-Sachs group, as is appropriate at null infinity. As an example, the Landau levels in ${\mathbb{R}}^3$ are shown to match those of a Dirac monopole on the dual ${\mathbb{S}}^2$, in the thermodynamic limit. This dual system is actually identified with a three-dimensional critical Ising model. The map is then realized on $N_f$ massive fermions in flat space which, indeed, are the hologram of $2N_f$ massless fermions on the cylinder. However, the dual space is really the conformal class of ${\mathbb{S}}^2\times \mathbb{R}$, naturally enclosing the universal cover of a conformally compactified four-dimensional anti–de Sitter (${\mathrm{AdS}}_4$) spacetime. We argue that, in the absence of interactions, the massless fermions on the conformal boundary are, in turn, dual to $N_f$ massive fermions in ${\mathrm{AdS}}_4$. For free fermions, all path integrals—the ones in ${\mathbb{R}}^4$ and ${\mathbb{S}}^2\times \mathbb{R}$ and ${\mathrm{AdS}}_4$—are shown to match. Hence, AdS/CFT duality emerges into a larger context, where one holography nests inside the other, suggesting a complete holographic bridge between fields in flat space and the AdS superstring.

We compute the particle creation rate in the context of quantum fields in curved spacetimes by evaluating the imaginary part of the effective action up to second order in the curvatures. For arbitrary metrics in dimensions $D\ge 4$, we express the vacuum persistence amplitude in terms of the Ricci scalar and the Weyl tensor, showing that, up to their second power, no particle creation occurs for conformal fields in conformally flat spacetimes. We pinpoint an analogy with the electromagnetic pair creation by writing the squared Weyl tensor invariant in terms of its electric and magnetic parts. In addition, we present an alternative expression for the imaginary part of the effective action employing the Cotton tensor. This is particularly useful in $D=3$, where the Weyl tensor trivially vanishes and the Cotton tensor is related to conformal flatness. Finally, we highlight the importance of the threshold for particle creation, a point that has been overlooked in some recent studies.

Results are presented for a semicoherent search for gravitational waves from the low-mass x-ray binary Scorpius X-1 in Observing Run 3 (O3) data from the Laser Interferometer Gravitational Wave Observatory, using an updated orbital parameter ephemeris and a hidden Markov model (HMM) to allow for spin wandering. The new orbital ephemeris corrects errors in previously published orbital measurements and implies a new search domain. This search domain does not overlap with the one used in the original Scorpius X-1 HMM O3 search. The corrected domain is approximately three times smaller by area in the $T_{\mathrm{asc}}\text{−}P$ plane than the original domain, where $T_{\mathrm{asc}}$ and $P$ denote the time of passage through the ascending node and the orbital period respectively, reducing the trials factor and computing time. No evidence is found for gravitational radiation in the search band from 60 to 500 Hz. Upper limits are computed for the characteristic gravitational wave strain. They are consistent with the values from the original Scorpius X-1 HMM O3 search.

Analogous to magnetism in electrodynamics, it is gravitomagnetism in relativistic gravity. Since gravity determines locally inertial frames, in general relativity (GR) and other relativistic theories of gravity, frame-dragging with source motion plays a key role in gravitomagnetism. Recently, Wu has put forward a gauge theory of gravity, called the gravitational quantum field theory (GQFT), with the gravitational force and the spin gauge force described by the gauge fields. Gao et al. [Phy. Rev. D 109, 064072] have derived the Shapiro time delay in the GQFT and given an empirical constraint from the Cassini experimental result on the dimensionless GQFT parameter ${\gamma }_W$ to be $(2.1\pm 2.3)\times {10}^{-5}$. In this work, we derive the frame-dragging Lense-Thirring effects in the GQFT. The current precision of LARES-LAGEOS Lense-Thirring measurement gives a constraint on $|{\gamma }_W|$ to be less than $2\times {10}^{-2}$. This constraint is consistent with, but subdominant to, the Cassini experimental constraint. As a candidate of quantum gravity, we do not expect that the deviation from the GR value (${\gamma }_W=0$) is large, classically. With the launch of LARES 2, the precision of the Lense-Thirring measurement is expected to increase by 1 order of magnitude in a couple of years. As to the Shapiro effect, current technologies have the capability to measure the ${\gamma }_W$ parameter to a precision of ${10}^{-9}$.

To investigate the detectability of holonomy corrected Schwarzschild black holes, we first derive the metric and geodesics for a test particle, as well as the conditions for circular orbits. Then, we derive the exact solution for the precessing orbits of a test particle in the holonomy corrected Schwarzschild black hole spacetime. We also provide preliminary bounds on the orbital parameters, considering the effects of these corrections on orbital precession. The precession deviations of the stellar orbits of S2, S4716, and hypothetical stars are calculated using preliminary bounds on the loop quantum gravity parameter $b$. We consider an extreme-mass-ratio inspiral system, where a stellar-mass black hole is inspiraling into a supermassive black hole. The periodic and quasiperiodic orbits of timelike particle around holonomy corrected Schwarzschild black holes, along with their corresponding gravitational waveforms, are investigated using the Levin and Perez-Giz classification of periodic orbits. These results provide new insights into distinguishing Schwarzschild black holes from holonomy corrected Schwarzschild black holes, offering not only a better understanding of the orbital dynamics of black holes but also new ideas for gravitational wave detection. In addition, this paper investigates the periodic orbits based on orbital eccentricity and the latus rectum, thereby opening up new avenues for research in periodic orbits. Our findings suggest that the orbital eccentricity has a more pronounced effect on the periodic orbits, while the loop quantum gravity parameter $b$ has minimal impact.

The gravitational-wave events observed by the LIGO-Virgo-KAGRA (LVK) Collaboration are attributed to compact binary coalescences happening in vacuum. However, several studies suggest that gaseous environments may play a significant role in the formation and evolution of compact binaries. Why have we not seen environmental effects in LVK signals? While matched filtering remains the most effective technique for gravitational-wave searches, it comes with a burden: we might only observe signals that align with our (vacuum) expectations, potentially missing unexpected or unknown phenomena. Even more concerning is the possibility that environmental effects could mimic vacuum waveforms, introducing biases in parameter estimation and impacting population studies. Here, we use numerical relativity simulations of binary black hole mergers inside stellar envelopes to show that (i) a GW150914-like event would be detected (with a false-alarm rate smaller than ${10}^{-4}{\mathrm{yr}}^{-1}$) using a template bank of vacuum waveforms, even when immersed in a stellar envelope of density larger than ${10}^7\mathrm{g}/{\mathrm{cm}}^3$, (ii) environmental effects can pass routinely performed tests of vacuum general relativity, while leading to considerable biases in parameter estimation, but (iii) phenomenological environment waveforms are effectual in detecting environmental effects and can resolve systematics.

Utilizing the Hamiltonian constraints approach, a quantum-corrected solution has been derived in Zhang et al., which describes either a regular black hole or a traversable wormhole, contingent upon the value of the quantum parameter. In this work, we compute the quasinormal modes associated with axial gravitational and test fields’ perturbations of these objects. We see that, due to quantum corrections near the event horizon, the first several overtones deviate from their Schwarzschild values at an increasing rate. The transition between the black hole and wormhole states is marked by modifications in the late-time signal. Our findings reveal that the fundamental quasinormal modes of quantum-corrected black holes exhibit only slight deviations from those of the classical Schwarzschild solution. However, at the transition, the spectrum undergoes significant changes, with the wormhole state characterized by exceptionally long-lived quasinormal modes. In addition, we calculate absorption cross sections of partial waves, greybody factors and energy emission rates of Hawking radiation.

The one-loop corrections (1LC) to the power spectrum of scalar perturbations arising from cubic interactions in the single-field E-type $\alpha$-attractor models of inflation and primordial black hole (PBH) production are numerically calculated. The results demonstrate the 1LC contributes merely a few percent to the tree-level power spectrum. The model parameters are chosen to predict the PBH masses in the asteroid-mass range, while maintaining consistency with the cosmic microwave background observations within $1\sigma$ confidence levels, and obeying the upper limits on $\mu$-distortions. The PBHs formed on scales smaller than the inflation scale can constitute a significant fraction of the present dark matter. The PBH-induced gravitational waves (GW) may be detectable by the future space-based gravitational interferometers. We also consider a reconstruction of the scalar potential from possible GW observations and present a numerical approach tested in the model parameter space.

In the single-field model, the preheating process occurs through self-resonance of the inflaton field. We study the nonlinear structures generated during preheating in the $\alpha$-attractor models and monodromy models. The potentials have a power law form $\propto {|\varphi |}^{2n}$ near the origin and a flat region away from bottom, which are consistent with current cosmological observations. The Floquet analysis shows that potential parameters in monodromy model have a significant influence on the region of resonance bands. Besides we investigate the formation of nonlinear structures, the equation of state, and the energy transfer through the ($3+1$) dimensional lattice simulation. We find that all the models exhibit similar nonlinear dynamics. Furthermore, our analysis reveals that the behavior of the inflation model at small field values, which is governed by the parameter $n$, exerts a more substantial influence on the nonlinear dynamics. The behavior at large field values, controlled by the parameter $q$, has a negligible impact.

Weak lensing surveys, along with most other late-Universe probes, have consistently measured a lower amplitude of the matter fluctuation spectrum, denoted by the parameter $S_8$, compared to predictions from early-Universe measurements in cosmic microwave background data. Improper modeling of nonlinear scales may partially explain these discrepancies in lensing surveys. This study investigates whether the conventional approach to addressing small scale biases remains optimal for Stage-IV lensing surveys. We demonstrate that conventional weak lensing estimators are affected by scale leakage from theoretical biases at nonlinear scales, which influence all observed scales. Using the BNT transform, we propose an $\ell$-cut methodology that effectively controls this leakage. The Bernardeau-Nishimichi-Taruya (BNT) transform reorganizes weak lensing data in $\ell$ space, aligning it with $k$ space, thereby reducing the mixing of nonlinear scales and providing a more accurate interpretation of the data. We evaluate the BNT approach by comparing hmcode, halofit, baryon correction model and axionhmcode mass power spectrum models using Euclid-like survey configurations. Additionally, we introduce a new estimator to quantify scale leakage in both the BNT and noBNT approaches. Our findings show that BNT outperforms traditional methods, preserving cosmological constraints while significantly mitigating theoretical biases.

Fast radio bursts (FRBs) are mysterious astrophysical transients whose origin and mechanism remain unclear. Compact object mergers may be a promising channel to produce some FRBs. Neutron star–black hole (NSBH) mergers could produce FRBs through mechanisms involving neutron star tidal disruption or magnetospheric disturbances. This could present an opportunity for multimessenger gravitational-wave observations, providing new insight into the nature of FRBs and nuclear matter. However, some of the gravitational-wave signals may be marginal detections with signal-to-noise ratios $<8$ or have large sky location and distance uncertainties, making it less straightforward to confidently associate an FRB with the gravitational-wave signal. One must therefore take care to avoid a false positive association. We demonstrate how to do this with simulated data. We calculate the posterior odds—a measurement of our relative belief for a common versus unrelated origin of a coincident NSBH and FRB. We find that a coincident $\mathrm{FRB}+\mathrm{NSBH}$ from a common source can yield a statistically significant posterior odds in a network with at least two observatories, but only if we require a coincidence in time and sky location, rather than time alone. However, we find that, for our model, we require a network signal-to-noise ratio greater than 10 to be confident in the common-source detection, when using a threshold of ln odds $>8$. We suggest that a coincident $\mathrm{NSBH}+\mathrm{FRB}$ detection could help distinguish between FRB engines by discriminating between disrupting and nondisrupting models.

Galactic core-collapse supernovae (CCSNe) are a target for current generation gravitational wave detectors with an expected rate of 1–3 per century. The development of data analysis methods used for their detection relies deeply on the availability of waveform templates. However, realistic numerical simulations producing such waveforms are computationally expensive (millions of CPU hours and ${10}^2–{10}^3\mathrm{GB}$ of memory), and only a few tens of them are available nowadays in the literature. We have developed a novel parametrized phenomenological waveform generator for CCSNe, ccphen v4, that reproduces the morphology of numerical simulation waveforms with low computational cost ($\sim 10\mathrm{ms}$ CPU time and a few MB of memory use). For the first time, the phenomenological waveforms include polarization and the effect of several oscillation modes in the protoneutron star. This is sufficient to describe the case of nonrotating progenitor cores, representing the vast majority of possible events. The waveforms include a stochastic component and are calibrated using numerical simulation data. The code is publicly available. Their main application is the training of neural networks used in detection pipelines, but other applications in this context are also discussed.

The fact that the standard dispersion relation for photons in vacuum could be modified because of their interaction with the quantum nature of spacetime has been proposed more than two decades ago. A quantitative model by Jacob and Piran has been tested extensively using distant highly energetic astrophysical sources, searching for energy-dependent time delays in photon arrival times. Since no delay was firmly measured, lower limits were set on the energy scale $\mathrm{\Lambda }$ related to these effects. In recent years, however, different but equally well-grounded expressions beyond the Jacob and Piran model were obtained for the photon dispersion relation, leading to different expressions for the dependence of lag versus redshift. This article introduces a general parametrization of modified dispersion relations in homogeneous and isotropic, i.e. cosmological, symmetry which directly leads to a general parametrized lag versus redshift dependence encompassing both existing and new models. This parametrization could be used in the future to compare the predicted time lags of the different models and test them against observations. To investigate this possibility, realistic datasets are simulated, mimicking different types of extragalactic sources as detected by current and future instruments. When no lag is injected in the simulated data, each lag-redshift model leads, as expected, to a different value for the limit on $\mathrm{\Lambda }$, and the Jacob and Piran model gives the most stringent bound. When a lag at $\mathrm{\Lambda }\sim E_P$ in the Jacob and Piran model is injected, it is detected for all the other lag-redshift relations considered, although leading to different values. Finally, the possibility to discriminate between several lag-redshift models is investigated, emphasizing the importance of an evenly distributed sample of sources across a wide range of redshifts.

In this article, we claim that axionlike particles (ALPs) with MeV masses can be produced with semirelativistic velocities in core-collapse supernovae (SNe), generating a diffuse galactic flux. We show that these ALPs can be detected in neutrino water Cherenkov detectors via $ap\to p\gamma$ interactions. Using Super-Kamiokande data, we derive new constraints on the ALP parameter space, excluding a region spanning more than one order of magnitude in the ALP-proton coupling above cooling bounds for ALP masses in the range of 1–80 MeV and ALP-proton couplings between $8\times {10}^{-6}–2\times {10}^{-4}$. We show that the future Hyper-Kamiokande will be able to probe couplings as small as $2.5\times {10}^{-6}$, fully closing the allowed region above SN 1987A cooling bounds.

The torsion pendulum is a prevailing instrument for measuring small forces acting on a solid body or those between solid bodies. While it offers powerful advantages, the measurement precision suffers from thermal noises of the suspending wires giving rise to stochastic torque noises. This paper proposes a new scheme to reduce the effect of such noise by employing a double torsion pendulum and cross-correlation technique. Cross-correlating two synthesized data streams which are composed of the rotation angles of two torsion stages, it yields the power spectral density estimate of external forces acting on the lower stage with the reduced effect from the thermal torque noises. As an example use case, we discuss the application to the study on the coupling strength of ultralight dark matter to standard model particles. Our evaluation indicates that the upper limit may be improved by an order of magnitude than the previous experiments at 2 mHz, which corresponds to about $8\times {10}^{-18}\mathrm{eV}$.

One potential factor that could impede searches for the stochastic gravitational-wave background (SGWB), arising from the incoherent superposition of a multitude of weak and unresolvable gravitational-wave signals in the Universe, is correlated magnetic noise at Earth-scale distances, such as the Schumann resonances. As the sensitivity of terrestrial detectors to SGWBs increases, these effects are expected to become even more pronounced, emphasizing the importance of considering correlated noise sources in SGWB searches. In this study, we explore for the first time the impact of this class of noise on anisotropic SGWB searches. We focus on the low-frequency range of 20–200 Hz with a resolution of $1/32\mathrm{Hz}$, using data from the LEMI-120 and Metronix MFS-06e magnetometers, located at the sites of the Advanced LIGO and Advanced Virgo interferometers, respectively, during the third observing run. These measurements were then compared with the directional upper limit derived from gravitational-wave data collected during the third observing run of the LIGO-Virgo-KAGRA Collaborations. The results indicate that the magnetic noise correlations are below the interferometers’ sensitivity level during the O3 observing run. The potential impact of magnetic correlations on the Advanced LIGO detectors has also been investigated at the $\mathrm{A}+$ design sensitivity level.

The shear $\eta$ and bulk $\zeta$ viscous coefficients have been calculated in a hot and chirally asymmetric quark matter quantified in terms of a chiral chemical potential (CCP) using the two-flavor Nambu-Jona–Lasinio (NJL) model. This is done by employing the one-loop Green-Kubo formalism where the viscous coefficients have been extracted from the long-wavelength limit of the in-medium spectral function corresponding to the energy momentum tensor (EMT) current correlator calculated using the real time formalism of finite temperature field theory. The momentum dependent thermal width of the quark/antiquark that enters into the expression of the viscosities as a dynamical input containing interactions, has been obtained from the $2\to 2$ scattering processes mediated via the collective mesonic modes in scalar and pseudoscalar channels encoded in respective in-medium polarization functions having explicit temperature and CCP dependence. Several thermodynamic quantities such as pressure, energy density, entropy density ($s$), specific heat and isentropic speed of sound have also been calculated at finite CCP. The temperature and CCP dependence of the viscosity to entropy density ratios $\eta /s$ and $\zeta /s$ have also been studied.

A one-loop Dyson-Schwinger-like resummation scheme is applied to scalar high-electric-charge compact objects (HECOs), extending previous work on spin-$\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.$ case. The electromagnetic interactions of HECOs are considered within the framework of strongly coupled scalar quantun electrodynamics. The resummation amounts to determining nontrivial ultraviolet (UV) fixed points, at which the effective Lagrangian, which will lead to the pertinent predictions on the cross sections, is computed. In contrast to the fermionic HECO case, in which the fixed point structure was determined solely by the interactions of the HECOs with the photon field, in the scalar case the existence of nontrivial UV fixed points requires the presence of additional strong self-interactions among the HECOs. Our resummation scheme, which is notably different from a lattice strong-coupling approach, makes the computation of the pertinent scalar-HECO-production cross sections reliable, thus allowing revisiting the mass bounds obtained from searches for such objects in current or future colliders. Our madgraph implementation of the results leads to enhanced (up to $\sim 30\%$) lower bounds on the mass of scalar HECOs, as compared to those extracted from the tree-level processes typically used in LHC collider searches by ATLAS and MoEDAL experiments.

We examine the correlations between new scalar boson decays to photons and electric dipole moments (EDMs) in the $CP$-violating flavor-aligned two-Higgs-doublet model (2HDM). It is convenient to work in the Higgs basis $\{{\mathcal{H}}_1,{\mathcal{H}}_2\}$ where only the first Higgs doublet field ${\mathcal{H}}_1$ acquires a vacuum expectation value. In light of the LHC Higgs data, which agree well with Standard Model (SM) predictions, it follows that the parameters of the 2HDM are consistent with the Higgs alignment limit. In this parameter regime, the observed SM-like Higgs boson resides almost entirely in ${\mathcal{H}}_1$, and the other two physical neutral scalars, which reside almost entirely in ${\mathcal{H}}_2$, are approximate eigenstates of $CP$ (denoted by the $CP$-even $H$ and the $CP$-odd $A$). In the Higgs basis, the scalar potential term ${\overline{Z}}_7{\mathcal{H}}_1^{†}{\mathcal{H}}_2{\mathcal{H}}_2^{†}{\mathcal{H}}_2+\mathrm{H}.\mathrm{c}.$ governs the charged-Higgs loop contributions to the decay of $H$ and $A$ to photons. If $\mathrm{Re}{\overline{Z}}_7\mathrm{Im}{\overline{Z}}_7\ne 0$, then $CP$-violating effects are present and allow for an $H^{+}{H}^{-}A$ coupling, which can yield a sizable branching ratio for $A\to \gamma \gamma$. These $CP$-violating effects also generate nonzero EDMs for the electron, the neutron and the proton. We examine these correlations for the cases of $m_A=95\mathrm{GeV}$ and $m_A=152\mathrm{GeV}$ where interesting excesses in the diphoton spectrum have been observed at the LHC. These excesses can be explained via the decay of $A$ while being consistent with the experimental bound for the electron EDM in regions of parameter space that can be tested with future neutron and proton EDM measurements. This allows for the interesting possibility where the 95 GeV diphoton excess can be identified with $A$, while $m_H\simeq 98\mathrm{GeV}$ can account for the best fit to the LEP excess in $e^{+}{e}^{-}\to ZH$ with $H\to b\overline{b}$.