A first order electroweak phase transition probes physics beyond the Standard Model on multiple frontiers and therefore is of immense interest for theoretical exploration. We conduct a model-independent study of the effects of relevant dimension 6 and dimension 8 operators, of the Standard Model effective field theory, on electroweak phase transition. We use a thermally corrected and renormalization group improved potential and study its impact on nucleation temperature. We then outline bubble dynamics that lead to ultrarelativistic bubble wall velocities which are mainly motivated from the viewpoint of gravitational wave detection. We highlight the ranges of the Wilson coefficients that give rise to such bubble wall velocities and predict gravitational wave spectra generated by such transitions which can be tested in future experiments.

The recent Belle II observation of $B\to K{E}_{\mathrm{miss}}$ challenges theoretical interpretations in terms of Standard Model neutrino final states. Instead, we consider new physics scenarios where up to two new light-invisible particles of spin 0 up to $3/2$ are present in the final state. We identify viable scenarios by reconstructing the (binned) likelihoods of the relevant $B\to K^{(*)}{E}_{\mathrm{miss}}$ and also $B_s\to E_{\mathrm{miss}}$ experimental analyses and present preferred regions of couplings and masses. In particular, we find that the current data prefer two-body decay kinematics involving the emission of a single massive scalar or a vector particle or, alternatively, three-body decays involving pairs of massive scalars or spin $1/2$ fermions. When applicable, we compare our findings with existing literature and briefly discuss some model-building implications.

The need to determine scattering amplitudes of few-hadron systems for arbitrary kinematics expands a broad set of subfields of modern-day nuclear and hadronic physics. In this work, we expand upon previous explorations on the use of real-time methods, like quantum computing or tensor networks, to determine few-body scattering amplitudes. Such calculations must be performed in a finite Minkowski spacetime, where scattering amplitudes are not well defined. Our previous work presented a conjecture of a systematically improvable estimator for scattering amplitudes constructed from finite-volume correlation functions. Here we provide further evidence that the prescription works for larger kinematic regions than previously explored as well as a broader class of scattering amplitudes. Finally, we devise a new method for estimating the order of magnitude of the error associated with finite time separations needed for such calculations. In units of the lightest mass of the theory, we find that to constrain amplitudes using real-time methods within $\mathcal{O}(10\%)$, the spacetime volumes must satisfy $mL\sim \mathcal{O}(10–{10}^2)$) and $mT\sim \mathcal{O}({10}^2–{10}^4)$.

Generalized parton distributions (GPDs) are key quantities for the description of a hadron’s three-dimensional structure. They are the current focus of all areas of hadronic physics—phenomenological, experimental and theoretical, including lattice QCD. Synergies between these areas are desirable and essential to achieve precise quantification and understanding of the structure of, particularly, nucleons, as the basic ingredients of matter. In this paper, we investigate, for the first time, the numerical implementation of the pseudodistribution approach for the extraction of zero-skewness GPDs for unpolarized quarks. Pseudodistributions are Euclidean parton correlators computable in lattice QCD that can be perturbatively matched to the light-cone parton distributions of interest. Although they are closely related to the quasidistributions and come from the same lattice-extracted matrix elements, they are, however, subject to different systematic effects. We use the data previously utilized for quasi-GPDs and extend it with other momentum transfers and nucleon boosts, in particular a higher one ($P_3=1.67\mathrm{GeV}$) with eightfold larger statistics than the largest one used for quasidistributions ($P_3=1.25\mathrm{GeV}$). We renormalize the matrix elements with a ratio scheme and match the resulting Ioffe time distributions to the light cone in coordinate space. The matched distributions are then used to reconstruct the $x$ dependence with a fitting Ansatz. We investigate some systematic effects related to this procedure, and we also compare the results with the ones obtained in the framework of quasi-GPDs. Our final results involve the invariant four-momentum transfer squared ($-t$) dependence of the flavor nonsinglet ($u-d$) $H$ and $E$ GPDs.

We investigate the chiral restoration and deconfinement phase transitions under an external magnetic field in the frame of a Pauli-Villars regularized Polyakov loop extended Nambu-Jona-Lasinio model. A running Polyakov loop scale parameter $T_0(eB)$ is introduced to mimic the reaction of the gluon sector to the presence of magnetic fields. It is found that a decreasing $T_0(eB)$ with magnetic fields can realize the inverse magnetic catalysis phenomena of chiral condensates of $u$ and $d$ quarks, increase of Polyakov loop, and the reduction of pseudocritical temperatures of chiral restoration and deconfinement phase transitions.

We calculate the cross sections of associated $J/\psi +{\psi }^{\prime }$ and $J/\psi +J/\psi$ production in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$ in the forward kinematic region. The high-energy factorization ($k_T$-factorization) framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution of gluon densities in a proton is applied. We demonstrate that the latest data on $J/\psi +J/\psi$ production and first experimental data on $J/\psi +{\psi }^{\prime }$ events taken very recently by the LHCb Collaboration can be described well by the color singlet terms and contributions from double parton scattering (DPS) with the standard choice for ${\sigma }_{\mathrm{eff}}$ parameter. The relative production rate $\sigma (J/\psi +{\psi }^{\prime })/\sigma (J/\psi +J/\psi )$ is found to be sensitive to the DPS terms as well as to feeddown contributions.

The Earth acts as a matter potential for relic neutrinos which modifies their index of refraction from vacuum by $\delta \sim {10}^{-8}$. It has been argued that the refractive effects from this potential should lead to a large $\mathcal{O}(\sqrt{\delta })$ neutrino-antineutrino asymmetry at the surface of the Earth. This result was computed by treating the Earth as flat. In this work, we revisit this calculation in the context of a perfectly spherical Earth. We demonstrate, both numerically and through analytic arguments, that the flat-Earth result is only recovered under the condition ${\delta }^{3/2}kR\gg 1$, where $k$ is the typical momentum of the relic neutrinos and $R$ is the radius of the Earth. This condition is required to prevent antineutrinos from tunneling into classically inaccessible trajectories below the Earth’s surface and washing away the large asymmetry. As the physical parameters of the Earth do not satisfy this condition, we find that the asymmetry at the surface should only be $\mathcal{O}(\delta )$. While the asphericity of the Earth may serve as a loophole to our conclusions, we argue that it is still difficult to generate a large asymmetry even in the presence of local terrain.

The DESI Collaboration have recently analyzed their first year of data, finding a preference for thawing dark energy scenarios when using parametrized equations of state for dark energy. We investigate whether this preference persists when the data are analyzed within the context of a well-studied field theory model of thawing dark energy, exponential quintessence. No preference for this model over Lambda cold dark matter is found, and both models are poorer fits to the data than the Chevallier-Polarski-Linder $w_0\text{−}{w}_a$ parametrization. We demonstrate that the worse fit is due to a lack of sharp features in the potential that results in a slowly evolving dark energy equation of state that does not have enough freedom to simultaneously fit the combination of the supernovae, DESI, and cosmic microwave background data. Our analysis provides guidance for constructing dynamical dark energy models that are able to better accommodate the data.

Heavy quarks created in heavy-ion collisions serve as an excellent probe of the produced quark-gluon plasma (QGP). The radiation pattern of jets formed from heavy quarks as they traverse the QGP exhibits a particularly interesting structure due to the interplay of two competing effects: the suppression of small-angle radiation, also known as the “dead-cone” effect, and the enhancement of emitted gluons by medium-induced radiation. In this Letter, we propose a new observable, based on the energy correlator approach to jet substructure, which will allow us to disentangle the two scales associated to these two phenomena and to determine under which conditions the dead cone is filled by medium-induced radiation. Combined with the forthcoming high-statistics measurements of heavy-flavor jets, this work provides a novel tool to unravel the dynamics of the QGP.

We discuss in detail the $1+1$-dimensional superconformal field theory dual to type II string theory on ${\mathrm{AdS}}_3\times S^3\times T^4$, emphasizing the string theoretic aspects of this duality. For one unit of Neveu-Schwarz (NS-NS) 5-brane flux ($Q_5=1$), this string theory has been suggested to be dual to a grand-canonical ensemble of $T^{4N}/S_N$ free symmetric orbifold conformal field theories (CFTs). We show how the string genus expansion emerges to all orders for the free orbifold grand-canonical correlation functions. We also discuss how the strong coupling limit of the NS-NS string theory arises (even at large $N$) in the free orbifold description, and argue why this limit does not have a weakly coupled RR description. The dual conformal field theory (CFT) includes (for all values of $Q_5$) an extra $T^4$ factor that is decoupled from perturbative string theory. We discuss the exactly marginal deformations that relate the different values of $Q_5$, including the precise $J\overline{J}$ deformations mixing this extra $T^4$ with the symmetric orbifold.

We construct a family of local static, vacuum five-dimensional solutions with two commuting spatial isometries describing a black hole with a $S^3$ horizon and a 2-cycle “bubble” in the domain of outer communications. The solutions are obtained by adding distortions to an asymptotically flat seed solution. We show that the conical singularities in the undistorted geometry can be removed by an appropriate choice of the distortion.

In this work, we study null hypersurfaces admitting a privileged vector field $\eta$ which is null and tangent at the hypersurface. We derive an identity that relates the deformation tensor of $\eta$ with tensor fields codifying the intrinsic and extrinsic geometry of the hypersurface. This is done without imposing restrictions either on the topology of the hypersurface or on the (possibly empty) subset of points where $\eta$ vanishes. We introduce a generalized notion of surface gravity $\kappa$ that extends smoothly the usual one to the fixed points. We also analyze the properties of the Lie derivative of the Levi-Civita connection along $\eta$. This analysis allows us to introduce three new notions of abstractly defined horizons (i.e., not necessarily viewed as embedded submanifolds) that we then compare with the standard concepts of nonexpanding, weakly isolated and isolated horizons. The former generalize the latter to completely general topologies and to horizons admitting fixed points. Finally, we study the structure of the fixed points on these new horizons.

We study electrically charged, static, spherically symmetric black holes in quadratic gravity using the conformal-to-Kundt technique, which leads to a considerable simplification of the field equations. We study the solutions using a Frobenius-like approach of power-series expansions. The indicial equations restrict the set of possible leading powers to a few cases, describing, e.g., black holes, wormholes, or naked singularities. We focus on the black hole case and derive recurrent formulas for all series coefficients of the infinite power-series expansion around the horizon. The solution is characterized by electric charge $q$, the black-hole radius $a_0$, and the Bach parameter $b$ related to the strength of the Bach tensor at the horizon. However, the Bach parameter has to be fine-tuned to ensure asymptotic flatness. The fine-tuning of $b$ for a given $q$ and $a_0$ returns up to two values, describing two branches of asymptotically flat, static, spherically symmetric, charged black holes in quadratic gravity. This is in agreement with previous numerical works. We discuss various physical properties of these black holes, such as their asymptotic mass, temperature, photon spheres, and black-hole shadows. A straightforward generalization to dyonic black holes in quadratic gravity is also briefly mentioned.

We explore the possibility of avoiding cosmological singularity with a bounce solution in the early Universe. The main finding is that simple and well-known semiclassical correction, which describes the mixing of radiation and gravity in the effective action, may provide an analytic solution with a bounce. The solution requires a positive beta function for the total radiation term and the contraction of the Universe at the initial instant. The numerical estimate shows that the bounce may occur in an acceptable range of energies, but only under strong assumptions about the particle physics beyond the Standard Model.

The hallmark of the four-parameter generalized entropy is that it can represent various known entropies proposed so far for suitable limits of the parameters, and thus the four-parameter generalized entropy can be applied on additive as well as on nonadditive systems. Following the proposal of the generalized entropy, it becomes important to constrain the corresponding parameters. In the present work, we intend to do this from the perspective of primordial gravitational waves (GWs) generated during inflation. In the background level, the generalized entropy successfully drives a viable and smooth evolution of the Universe, particularly from inflation to reheating followed by a radiation era, for certain ranges of the entropic parameters. Consequently we investigate whether such viable ranges of the entropic parameters (coming from the background level) allow the primordial GWs spectrum to pass through the sensitivity curves of various GWs observatories. Therefore, if the future observatories can detect the signal of primordial GWs, then our theoretical expectation carried in the present work may provide a possible tool for the measurement of the generalized entropic parameters.

We calculate the tensor bispectrum mediated by an excited scalar field during inflation and find that the bispectrum peaks in the squeezed configuration, which is different from that of gravitational waves induced by enhanced curvature perturbations reentering the horizon in the radiation-dominated era. Measuring the bispectrum provides a promising way to distinguish the stochastic gravitational-wave background generated during inflation from that generated after inflation.

We show that dark matter with certain minimal properties can convert the majority of baryons in galaxies to black holes over hundred trillion year timescales. We argue that this has implications for cosmologies which propose that new universes are created in black hole interiors. We focus on the paradigm of cosmological natural selection, which connects black hole production to a universe’s likelihood for existing. Further, we propose that the Universe’s timescale for entropy production could be dynamically linked to black hole production in a naturally selected universe. Our Universe would fit this scenario for models of particle dark matter that convert helium white dwarfs to black holes in around a hundred trillion years, where the dominant source of entropy in our Universe is the helium white dwarfs’ stellar progenitors, which cease forming and burning also in around a hundred trillion years. Much of this dark matter could be discovered at ongoing experiments.

We study gravitational wave production during kinetic preheating after inflation with a focus on scenarios that arise in $\alpha$-attractor models where a scalar dilatonlike inflaton is kinetically coupled to a second scalar field. We present high-resolution lattice simulations of three $\alpha$-attractor models for a range of parameters to probe regions where preheating is efficient. We find that preheating in these models can be extremely violent, resulting in gravitational wave energy densities that can be constrained by cosmic microwave background measurements of the effective number of relativistic species, $N_{\mathrm{eff}}$.

We investigate a self-interacting dark matter model featuring a velocity-dependent cross section with an order-of-magnitude resonant enhancement of the cross section at $\sim 16\mathrm{km}{\mathrm{s}}^{-1}$. To understand the implications for the structure of dark matter halos, we perform N-body simulations of isolated dark matter halos of mass $\sim {10}^8{M}_{\odot }$, a halo mass selected to have a maximum response to the resonance. We track the core formation and the gravothermal collapse phases of the dark matter halo in this model and compare the halo evolving with the resonant cross section with halos evolving with velocity-independent cross sections. We show that dark matter halo evolution with the resonant cross section exhibits a deviation from universality that characterizes halo evolution with velocity-independent cross sections. The halo evolving under the influence of the resonance reaches a lower minimum central density during core formation. It subsequently takes about 20% longer to reach its initial central density during the collapse phase. These results motivate a more detailed exploration of halo evolution in models with pronounced resonances.

We study the impact of gravitational wave memory on the distribution of far away light sources in the sky. For the first time, we compute the buildup of small, but permanent tensor distortions of the metric over cosmological timescales using realistic models of compact binary coalescences whose rate of occurrence is extrapolated at $z\sim \mathcal{O}(1)$. This allows for a consistent computation of the random-walk-like evolution of gravitational wave memory which, in turn, is used to estimate the overall shape and magnitude of astrometric deflections of far away sources of light. We find that, for pulsar or quasar proper motions, the near-Earth contribution to the astrometric deflections dominates the result and the deflection is analogous to a stochastic gravitational wave memory background that is generally subdominant to the primary stochastic gravitational wave background. We find that this contribution can be within the reach of future surveys such as Theia. Finally, we also study the deviation of the presently observed angular distribution of quasars from perfect isotropy, which arises from the slow buildup of gravitational wave memory over the entire history of the Universe. In this case, we find that astrometric deflections depend on the entire light trajectory from the source to Earth, yielding a quadrupole pattern whose magnitude is unlikely to be within reach of the next generation of astrometric surveys due to shot noise and cosmic variance limitations.