We investigate the dynamics of two coherently coupled dissipative time crystals. In the classical mean-field limit of infinite spin length, we identify a regime of chaotic synchronization, marked by a positive largest Lyapunov exponent and a Pearson correlation coefficient close to one. At the boundary of this regime, the Pearson coefficient varies abruptly, marking a crossover between staggered and uniform $z$-magnetization. To address finite-size quantum dynamics, we employ a quantum-trajectory approach and study the trajectory-resolved expectations of subsystem $z$-magnetizations. Their histograms over time and trajectory realizations exhibit maxima that undergo a staggered-to-uniform crossover analogous to the classical one. In analogy with the classical case, we interpret this behavior as quantum chaotic synchronization, with dissipative quantum chaos evidenced by the steady-state density matrix exhibiting Gaussian Unitary Ensemble statistics. The locations of the classical and quantum crossover differ, reflecting the noncommutativity of the infinite-spin and infinite-time limits and the impact of entanglement, quantified via the entanglement entropy between subsystems.

The presence of a topological susceptibility in the electroweak sector of the Standard Model implies the existence of a pseudoscalar state in the spectrum, $\eta_W$. We show that, within the Standard Model, no new particle is required to form this state. We identify the $\eta_W$ state with the CP-odd linear combination of the ground states of hydrogen and antihydrogen atoms.

We present strong evidence for dynamical dark energy challenging the $\Lambda$CDM model. Several dark energy models are explored, including $\omega_0\omega_a$CDM, logarithmic, Exponential, JBP, and BA, along with non-flat cosmologies accounting for potential spatial curvature. Our analysis supports a flat Universe ($\Omega_k \approx 0$). Using the Metropolis-Hastings MCMC algorithm, we analyze data from BAO of DESI DR2, Type Ia Supernovae, and CMB to constrain model parameters. We find strong evidence that $\omega \neq -1$, with deviations from $\Lambda$CDM favoring dynamical dark energy consistent with the Quintom-B scenario (\omega_0 > -1, \omega_a < 0, and \omega_0 + \omega_a < -1). We also derive upper bounds on $\sum m_\nu$ from CMB + DESI DR2. For $\Lambda$CDM we find \sum m_\nu < 0.066~\text{eV}, while for $\omega$CDM it is \sum m_\nu < 0.075~\text{eV}. In o$\Lambda$CDM and o$\omega$CDM the limits are \sum m_\nu < 0.263~\text{eV} and \sum m_\nu < 0.520~\text{eV}, respectively. For other models, including $\omega_0\omega_a$CDM, Logarithmic, Exponential, JBP, BA, and GEDE, the upper limits range from < 0.043~\text{eV} to < 0.127~\text{eV}. Constraints on the effective number of relativistic species, $N_{\text{eff}}$, remain consistent with the standard value $N_{\text{eff}} = 3.044$ for all models. Bayesian evidence shows that combining DES-SN5Y and Union3 SNe Ia with CMB + DESI DR2 reveals deviations from $\Lambda$CDM. Finally, while no model reaches the $5\sigma$ threshold, some show > 3\sigma tensions with DES-SN5YR or Union3, hinting at cracks in the cosmological constant $\Lambda$.

Lie-Poisson electrodynamics describes a semi-classical approximation of noncommutative $U(1)$ gauge theories with Lie-algebra-type noncommutativities. We obtain a gauge-invariant local classical action with the correct commutative limit for a generic Lie-Poisson gauge model. At the semi-classical level, our results provide a relatively simple solution to the old problem of constructing an admissible Lagrangian formulation for the $U(1)$ gauge theory on the four-dimensional $\kappa$-Minkowski space-time. In particular, we derive an explicit expression for the classical action which yields the deformed Maxwell equations previously proposed in JHEP 11 (2023) 200 for this noncommutativity on general grounds.

As part of the Galactic Bulge Time Domain Survey (GBTDS), the Nancy Grace Roman Galactic Exoplanet Survey (RGES) will use microlensing to discover cold outer planets and free-floating planets unbound to stars. NASA has established several science requirements for the GBTDS to ensure RGES success. A key advantage of RGES is Roman's high angular resolution, which will allow detection of flux from many host stars. One requirement specifies that Roman must measure the masses and distances of 40% of detected planet hosts with 20% precision or better. To test this, we simulated microlensing events toward the GBTDS fields and used Fisher matrix analysis to estimate light curve parameter uncertainties. Combining these with Roman imaging observables (lens flux, relative lens-source proper motion), we estimated the achievable precision of lens mass and distance measurements. Using pyLIMASS, a publicly available code for estimating lens properties, we applied this analysis to 3,000 simulated events. Assuming the Cassan et al. (2012) exoplanet mass function, we find that >40% of host stars meet the required 20% precision threshold, confirming that the GBTDS can satisfy the mission requirement. We validated our approach by comparing our inferred lens masses and distances to empirical measurements from detailed image-constrained light curve modeling of historical microlensing events with Hubble and Keck follow-up imaging. Our results agree within roughly 1 sigma, demonstrating that both approaches yield consistent and reliable mass and distance estimates, and confirming the robustness of our simulations for Roman-era microlensing science.

We study the behavior of magic as a bipartite correlation in the quantum Ising chain across its quantum phase transition, and at finite temperature. In order to quantify the magic of partitions rigorously, we formulate a hybrid scheme that combines stochastic sampling of reduced density matrices via quantum Monte Carlo, with state-of-the-art estimators for the robustness of magic - a {\it bona fide} measure of magic for mixed states. This allows us to compute the mutual robustness of magic for partitions up to 8 sites, embedded into a much larger system. We show how mutual robustness is directly related to critical behaviors: at the critical point, it displays a power law decay as a function of the distance between partitions, whose exponent is related to the partition size. Once finite temperature is included, mutual magic retains its low temperature value up to an effective critical temperature, whose dependence on size is also algebraic. This suggests that magic, differently from entanglement, does not necessarily undergo a sudden death.

Although debate on DESI DR1 systematics remains, DESI DR2 is consistent with DR1 and strengthens its trends. In our analysis, the LRG1 point at $z_{\mathrm{eff}}=0.510$ and the LRG3+ELG1 point at $z_{\mathrm{eff}}=0.934$ are in tension with the $\Lambda$CDM-anchored $\Omega_m$ inferred from Planck and SNe Ia (Pantheon$^{+}$, Union3, DES-SN5YR): for LRG1 the tensions are $2.42\sigma$, $1.91\sigma$, $2.19\sigma$, and $2.99\sigma$; for LRG3+ELG1 they are $2.60\sigma$, $2.24\sigma$, $2.51\sigma$, and $2.96\sigma$. Across redshift bins DR2 shows improved agreement relative to DR1, with the $\Omega_m$ tension dropping from $2.20\sigma$ to $1.84\sigma$. Nevertheless, DR2 alone is not decisive against $\Lambda$CDM, and the apparent deviation is driven mainly by LRG1 and LRG2. In a $\omega_0\omega_a$CDM fit using all tracers we find a posterior mean with $w_0>-1$, consistent with dynamical dark energy and nominally challenging $\Lambda$CDM. Removing LRG1 and/or LRG2 restores $\Lambda$CDM concordance ($\omega_0\to-1$); moreover, $\omega_0^{\mathrm{(LRG2)}}>w_0^{\mathrm{(LRG1)}}$, indicating that LRG2 drives the trend more strongly. Model selection via the natural-log Bayes factor $\ln\mathrm{BF}\equiv\ln(Z_{\Lambda\mathrm{CDM}}/Z_{\omega_0\omega_a\mathrm{CDM}})$ yields weak evidence for $\Lambda$CDM when LRG1, LRG2, or both are removed, and is inconclusive for the full sample. Hence the data do not require the extra $\omega_a$ freedom, and the apparent $\omega_0>-1$ preference should be interpreted cautiously as a reflection of the $\omega_0$$\omega_a$ degeneracy with limited per-tracer information.

Quantum groups have been widely explored as a tool to encode possible nontrivial generalisations of reference frame transformations, relevant in quantum gravity. In quantum information, it was found that the reference frames can be associated to quantum particles, leading to quantum reference frames transformations. The connection between these two frameworks is still unexplored, but if clarified it will lead to a more profound understanding of symmetries in quantum mechanics and quantum gravity. Here, we establish a correspondence between quantum reference frame transformations and transformations generated by a quantum deformation of the Galilei group with commutative time, taken at first order in the quantum deformation parameter. This is found once the quantum group noncommutative transformation parameters are represented on the phase space of a quantum particle, and upon setting the quantum deformation parameter to be proportional to the inverse of the mass of the particle serving as the quantum reference frame. These results allow us to show that quantum reference frame transformations are physically relevant when the state of the quantum reference frame is in a quantum superposition of semiclassical states. We conjecture that the all-order quantum Galilei group describes quantum reference frame transformations between more general quantum states of the quantum reference frame.

We investigate the efficiency of different quantum Monte Carlo simulations of a pair of antiferromagnetically coupled qubits in an Ohmic dissipative environment. Using a Trotter-Suzuky decomposition and integrating out the degrees of freedom of the thermal bath, the model maps onto a frustrated long-range double-chain Ising lattice. We prove that: i) due to frustration, the conventional Swendsen-Wang approach to cluster dynamics turns out to suffer from a severe inefficiency, stemming from the mismatch between spin correlations and cluster connectivity; ii) the Kandel-Domany approach is extremely effective in the study of dissipative quantum qubits. We partition the double-chain into different types of plaquettes and minimize the weight of graphs containing antiferromagnetic bonds by using both analytic and numerical approaches. Monte Carlo simulation results show that ``long range'' plaquette decompositions are more efficient than the ``local'' ones, especially for high levels of dissipation.

Quantum state complexity metrics, such as anticoncentration and magic, offer key insights into many-body physics, information scrambling, and quantum computing. Anticoncentration and equilibration of magic under dynamics of random quantum circuits occur at times scaling logarithmically with system size, a prediction that is believed to extend to more general ergodic dynamics. This work challenges this idea by examining the anticoncentration and magic spreading in one-dimensional ergodic Floquet models and Hamiltonian systems. Using participation and stabilizer entropies to probe these resources, we reveal significant differences between the two this http URL systems align with random circuit predictions, exhibiting anticoncentration and saturation of magic at time scales that increase logarithmically with system size. In contrast, Hamiltonian dynamics deviate from the random circuit predictions and require times scaling approximately linearly with system size to achieve saturation of participation and stabilizer entropies, which remain smaller than that of the typical quantum states even in the long-time limit. Our findings establish the phenomenology of participation and entropy growth in ergodic many-body systems and emphasize the role of energy conservation in constraining anticoncentration and magic dynamics.

The long range spatial and temporal ordering displayed by discrete time crystals, can become advantageous properties when used for sensing extremely weak signals. Here, we investigate their performance as quantum sensors of weak AC-fields and demonstrate, using the quantum Fisher information measure, that they can overcome the shot noise limit while allowing long interrogation times. In such systems, collective interactions stabilize their dynamics against noise making them robust enough to protocol imperfections.

Monitored quantum systems, where unitary dynamics compete with continuous measurements, exhibit dynamical transitions as the measurement rate is varied. These reflect abrupt changes in the structure of the evolving wavefunction, captured by complementary complexity diagnostics that include and go beyond entanglement aspects. Here, we investigate how monitoring affects magic state resources, the nonstabilizerness, of Gaussian fermionic systems. Using scalable Majorana sampling techniques, we track the evolution of stabilizer Rényi entropies in large systems under projective measurements. While the leading extensive (volume-law) scaling of magic remains robust across all measurement rates, we uncover a sharp transition in the subleading logarithmic corrections. This measurement-induced complexity transition, invisible to standard entanglement probes, highlights the power of magic-based diagnostics in revealing hidden features of monitored many-body dynamics.

Processes commonly studied at the Large Hadron Collider (LHC) are induced by quarks and gluons inside the protons of the LHC beams. In this letter we demonstrate that, since protons also contain leptons, it is possible to target lepton-induced processes at the LHC as well. In particular, by picking a lepton from one beam and a quark from the other beam, we present for the first time a comprehensive analysis of resonant single leptoquark (LQ) production at a hadron collider. In the case of minimal scalar LQs, we derive novel bounds that arise from the LHC Run II considering all possible flavour combinations of an electron or a muon and an up ($u$), a down ($d$), a strange or a charm quark. For the flavour combinations with a $u$ or a $d$ quark, the obtained limits represent the most stringent constraints to date on LQs of this type. The prospects of our method at future LHC runs are also explored. Given the discovery reach of the proposed LQ signature, we argue that dedicated resonance searches in final states featuring a single light lepton and a single light-flavour jet should be added to the exotics search canon of both the ATLAS and the CMS collaboration.

The second Gravitational-Wave Transient Catalog reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15:00 UTC and 1 October 2019 15:00 UTC. We present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the astrophysical probability for each candidate event. While GWTC-2 used a false alarm rate threshold of 2 per year, we include in GWTC-2.1, 1201 candidates that pass a false alarm rate threshold of 2 per day. We calculate the source properties of a subset of 44 high-significance candidates that have an astrophysical probability greater than 0.5. Of these candidates, 36 have been reported in GWTC-2. If the 8 additional high-significance candidates presented here are astrophysical, the mass range of events that are unambiguously identified as binary black holes (both objects $\geq 3M_\odot$) is increased compared to GWTC-2, with total masses from $\sim 14 M_\odot$for GW190924_021846 to$\sim 182 M_\odot$ for GW190426_190642. The primary components of two new candidate events (GW190403_051519 and GW190426_190642) fall in the mass gap predicted by pair instability supernova theory. We also expand the population of binaries with significantly asymmetric mass ratios reported in GWTC-2 by an additional two events (the mass ratio is less than $0.65$ and $0.44$ at $90\%$ probability for GW190403_051519 and GW190917_114630 respectively), and find that 2 of the 8 new events have effective inspiral spins \chi_\mathrm{eff} > 0 (at $90\%$ credibility), while no binary is consistent with \chi_\mathrm{eff} < 0 at the same significance.

We report on an improved measurement of the Cabibbo-Kobayashi-Maskawa {\it CP}-violating phase $\gamma$ through a Dalitz plot analysis of neutral $D$ meson decays to $K_S^0 \pi^+ \pi^-$ and $K_S^0 K^+ K^-$ in the processes $B^\mp \to D K^\mp$, $B^\mp \to D^* K^\mp$ with $D^* \to D\pi^0,D\gamma$, and $B^\mp \to D K^{*\mp}$ with $K^{*\mp} \to K_S^0 \pi^\mp$. Using a sample of 383 million $B\bar{B}$ pairs collected by the BABAR detector, we measure $\gamma=(76 \pm 22 \pm 5 \pm 5)^\circ$ (mod $180^\circ$), where the first error is statistical, the second is the experimental systematic uncertainty and the third reflects the uncertainty on the description of the Dalitz plot distributions. The corresponding two standard deviation region is 29^\circ < \gamma < 122^\circ. This result has a significance of direct {\it CP} violation ($\gamma \ne 0$) of 3.0 standard deviations.

This letter presents the measurement of the energy-dependent neutrino-nucleon cross section in tungsten and the differential flux of muon neutrinos and anti-neutrinos. The analysis is performed using proton-proton collision data at a center-of-mass energy of $13.6 \, {\rm TeV}$ and corresponding to an integrated luminosity of $(65.6 \pm 1.4) \, \mathrm{fb^{-1}}$. Using the active electronic components of the FASER detector, $338.1 \pm 21.0$ charged current muon neutrino interaction events are identified, with backgrounds from other processes subtracted. We unfold the neutrino events into a fiducial volume corresponding to the sensitive regions of the FASER detector and interpret the results in two ways: We use the expected neutrino flux to measure the cross section, and we use the predicted cross section to measure the neutrino flux. Both results are presented in six bins of neutrino energy, achieving the first differential measurement in the TeV range. The observed distributions align with Standard Model predictions. Using this differential data, we extract the contributions of neutrinos from pion and kaon decays.

Known methods for transverse confinement and guidance of light can be grouped into a few basic mechanisms, the most common being metallic reflection, total internal reflection and photonic-bandgap (or Bragg) reflection. All of them essentially rely on changes of the refractive index, that is on scalar properties of light. Recently, processes based on "geometric Berry phases", such as manipulation of polarization states or deflection of spinning-light rays, have attracted considerable interest in the contexts of singular optics and structured light. Here, we disclose a new approach to light waveguiding, using geometric Berry phases and exploiting polarization states and their handling. This can be realized in structured three-dimensional anisotropic media, in which the optic axis lies orthogonal to the propagation direction and is modulated along it and across the transverse plane, so that the refractive index remains constant but a phase distortion can be imposed on a beam. In addition to a complete theoretical analysis with numerical simulations, we present a proof-of-principle experimental demonstration of this effect in a discrete element implementation of a geometric phase waveguide. The mechanism we introduce shows that spin-orbit optical interactions can play an important role in integrated optics and paves the way to an entire new class of photonic systems that exploit the vectorial nature of light.