The common statement that any consistent quantum gravity theory contains dynamical objects with all possible charges suggests that there are still a number of hitherto-unidentified branes in string theory. Here we give the exact worldsheet description of near-horizon limits of nonsupersymmetric $p$-branes in ten-dimensional $\text{Spin}(32)/{\mathbb{Z}}_2$ or $(E_8\times E_8)⋊{\mathbb{Z}}_2$ heterotic superstring theories for $p=7$, 6, 4, 0.

We show that supersymmetric supergravity solutions with an $R$-symmetry Killing vector are equipped with a set of equivariantly closed forms. Various physical observables may be expressed as integrals of these forms, and then evaluated using the Berline-Vergne-Atiyah-Bott fixed point theorem. We illustrate with a variety of holographic examples, including on-shell actions, black hole entropies, central charges, and scaling dimensions of operators. The resulting expressions depend only on topological data and the $R$-symmetry vector, and hence may be evaluated without solving the supergravity equations.

Quantum simulation is a powerful tool to study the properties of quantum systems. The dynamics of open quantum systems are often described by completely positive ($CP$) maps, for which several quantum simulation schemes exist. Such maps, however, represent only a subset of a larger class of maps: the general dynamical maps which are linear, Hermitian preserving, and trace preserving but not necessarily positivity preserving. Here we present a simulation scheme for these general dynamical maps, which occur when the underlying system-reservoir model undergoes entangling (and thus non-Markovian) dynamics. Such maps also arise as the inverse of $CP$ maps, which are commonly used in error mitigation. We illustrate our simulation scheme on an IBM quantum processor, demonstrating its ability to recover the initial state of a Lindblad evolution. This paves the way for a novel form of quantum error mitigation. Our scheme only requires one ancilla qubit as an overhead and a small number of one and two qubit gates. Consequently, we expect it to be of practical use in near-term quantum devices.

We make the case that there can be no low-redshift solution to the $H_0$ tension. To robustly answer this question, we use a very flexible parametrization for the dark energy equation of state such that every cosmological distance still allowed by data exists within this prior volume. To then answer whether there exists a satisfactory solution to the $H_0$ tension within this comprehensive parametrization, we constrained the parametric form using different partitions of the Planck cosmic microwave background, SDSS-IV/eBOSS DR16 baryon acoustic oscillation, and Pantheon supernova datasets. When constrained by just the cosmic microwave background dataset, there exists a set of equations of state which yields high $H_0$ values, but these equations of state are ruled out by the combination of the supernova and baryon acoustic oscillation datasets. In other words, the constraint from the cosmic microwave background, baryon acoustic oscillation, and supernova datasets together does not allow for high $H_0$ values and converges around an equation of state consistent with a cosmological constant. Thus, since this very flexible parametrization does not offer a solution to the $H_0$ tension, there can be no solution to the $H_0$ tension that adds physics at only low redshifts. This is directly related to the expansion history of the Universe and its geometrical properties and would include models beyond those parametrized by $w(z)$.

Starburst galaxies are well-motivated astrophysical emitters of high-energy gamma rays. They are well-known cosmic-ray “reservoirs,” thanks to their expected large magnetic field turbulence which confine high-energy protons for $\sim {10}^5\mathrm{years}$. Over such long times, cosmic-ray transport can be significantly affected by scatterings with sub-GeV dark matter. Here we point out that this scattering distorts the cosmic-ray spectrum, and the distortion can be indirectly observed by measuring the gamma rays produced by cosmic rays via hadronic collisions. Present gamma-ray data show no sign of such a distortion, leading to stringent bounds on the cross section between protons and dark matter. These are highly complementary with current bounds and have large room for improvement with the future gamma-ray measurements in the 0.1–10 TeV range from the Cherenkov Telescope Array, which can strengthen the limits by as much as 2 orders of magnitude.

Axions can be copiously produced in localized regions of neutron star magnetospheres where the ambient plasma is unable to efficiently screen the induced electric field. As these axions stream away from the neutron star they can resonantly transition into photons, generating a large broadband contribution to the neutron star’s intrinsic radio flux. In this Letter, we develop a comprehensive end-to-end framework to model this process from the initial production of axions to the final detection of radio photons, and derive constraints on the axion-photon coupling, $g_{a\gamma \gamma }$, using observations of 27 nearby pulsars. We study the modeling uncertainty in the sourced axion spectrum by comparing predictions from 2.5 dimensional particle-in-cell simulations with those derived using a semianalytic model; these results show remarkable agreement, leading to constraints on the axion-photon coupling that typically differ by a factor of no more than $\sim 2$. The limits presented here are the strongest to date for axion masses ${10}^{-8}\mathrm{eV}\lesssim m_a\lesssim {10}^{-5}\mathrm{eV}$, and crucially do not rely on the assumption that axions are dark matter.

The large scale limit of the galaxy power spectrum provides a unique window into the early Universe through a possible detection of scale dependent bias produced by primordial non Gaussianities. On such large scales, relativistic effects could become important and be confused for a primordial signal. In this Letter we provide the first consistent estimate of such effects in the observed galaxy power spectrum, and discuss their possible degeneracy with local primordial non Gaussianities. We also clarify the physical differences between the two signatures, as revealed by their different sensitivity to the large scale gravitational potential. Our results indicate that, while relativistic effects could easily account for 10% of the observed power spectrum, the subset of those with a similar scale dependence to a primordial signal can be safely ignored for current galaxy surveys, but it will become relevant for future observational programs.

The majority of extensions to general relativity (GR) display mathematical pathologies—higher derivatives, character change in equations that can be classified within partial differential equation theory, and even unclassifiable ones—that cause severe difficulties to study them, especially in dynamical regimes. We present here an approach that enables their consistent treatment and extraction of physical consequences. We illustrate this method in the context of single and merging black holes in a highly challenging beyond GR theory.

We construct generalized symmetries for linearized Einstein gravity in arbitrary dimensions. First-principle considerations in quantum field theory force generalized symmetries to appear in dual pairs. Verifying this prediction helps us find the full set of nontrivial conserved charges—associated, in equal parts, with 2-form and ($D-2$)-form currents. Their total number is $D(D+1)$. We compute the quantum commutators of pairs of dual charges, showing that they are nonvanishing for regions whose boundaries are nontrivially linked with each other and zero otherwise, as expected on general grounds. We also consider general linearized higher-curvature gravities. These propagate, in addition to the usual graviton, a spin-0 mode as well as a massive ghostlike spin-2 mode. When the latter is absent, the theory is unitary and the dual-pairs principle is respected. In particular, we find that the number and types of charges remain the same as for Einstein gravity, and that they correspond to continuous generalizations of the Einsteinian ones.

The ${}^{22}\mathrm{Mg}(\alpha ,p){}^{25}\mathrm{Al}$ reaction rate has been identified as a major source of uncertainty for understanding the nucleosynthesis flow in Type-I x-ray bursts. We report a direct measurement of the energy- and angle-integrated cross sections of this reaction in a 3.3–6.9 MeV center-of-mass energy range using the MUlti-Sampling Ionization Chamber (MUSIC). The new ${}^{22}\mathrm{Mg}(\alpha ,p){}^{25}\mathrm{Al}$ reaction rate is a factor of $\sim 4$ higher than the previous direct measurement of this reaction within temperatures relevant for x-ray bursts, resulting in the ${}^{22}\mathrm{Mg}$ waiting point of x-ray burst nucleosynthesis flow to be significantly bypassed via the $(\alpha ,p)$ reaction.

We study the kinematics and dynamics of a highly compliant membrane disk placed head-on in a uniform flow. With increasing flow velocity, the membrane deforms nonlinearly into increasingly parachutelike shapes. These aerodynamically elongated materials exhibit a modified drag law, which is linked to the elastohydrodynamic interactions. We predict the unsteady structural response of the membranes using a nonlinear, aeroelastic model—in excellent agreement with experimental measurements of deformations and force fluctuations. With simultaneous membrane interface tracking, force measurements and flow tracing, we reveal that a peculiar skewness in the membrane’s oscillations triggers turbulence production in the wake, thereby modulating the drag. The present work provides a demonstration of the complex interplay between soft materials and fluid turbulence, leading to new, emergent system properties.

Here we report a combined study of low-temperature scanning tunneling microscopy and dynamical mean-field theory on ${\mathrm{PdCrO}}_2$, a delafossite metal with an antiferromagnetic order below $\sim 37.5\mathrm{K}$. First, on the ${\mathrm{CrO}}_2$-terminated polar surface we detect a gaplike feature both below and above the Néel temperature. The dynamical mean-field theory calculations indicate that this gap is opened due to the strong correlations of $\mathrm{Cr}\text{−}3d$ electrons, suggesting the hidden Mott nature of the gap. Then, we observe two kinds of Pd-terminated polar surfaces. One is a well-ordered Pd surface with the Fermi-surface-nesting-induced incommensurate charge modulation, while the other one is a reconstructed Pd surface with the individual nanoscale nonperiodic domain structures. On the well-ordered Pd surface, the interference between the incommensurate charge modulation and the atomic lattice forms the periodic moiré pattern. Our results provide important microscopic information for fully understanding the correlated electronic properties of this class of materials.

More than twenty years ago, multiferroic compounds combining in particular magnetism and ferroelectricity were rediscovered. Since then, ${\mathrm{BiFeO}}_3$ has emerged as the most outstanding multiferroic by combining at room temperature almost all the fundamental or applicative properties that may be desired: electroactive spin wave excitations called electromagnons, conductive domain walls, or a low band gap of interest for magnonic devices. All these properties have so far only been discontinuously strain engineered in thin films according to the lattice parameter imposed by the substrate. Here we explore the ferroelectricity and the dynamic magnetic response of ${\mathrm{BiFeO}}_3$ bulk under continuously tunable uniaxial strain. Using elasto-Raman spectroscopy, we show that the ferroelectric soft mode is strongly enhanced under tensile strain and driven by the volume preserving deformation at low strain. The magnonic response is entirely modified with low energy magnon modes being suppressed for tensile strain above pointing out a transition from a cycloid to an homogeneous magnetic state. Effective Hamiltonian calculations show that the ferroelectric and the antiferrodistortive modes compete in the tensile regime. In addition, the homogeneous antiferromagnetic state becomes more stable compared to the cycloidal state above a $+2\%$ tensile strain close to the experimental value. Finally, we reveal the ferroelectric and magnetic orders of ${\mathrm{BiFeO}}_3$ under uniaxial strain and how the tensile strain allows us to unlock and to modify in a differentiated way the polarization and the magnetic structure.

Josephson junctions in InAs nanowires proximitized with an Al shell can host gate-tunable Andreev bound states. Depending on the bound state occupation, the fermion parity of the junction can be even or odd. Coherent control of Andreev bound states has recently been achieved within each parity sector, but it is impeded by incoherent parity switches due to excess quasiparticles in the superconducting environment. Here, we show that we can polarize the fermion parity dynamically using microwave pulses by embedding the junction in a superconducting LC resonator. We demonstrate polarization up to $94\%\pm 1\%$ ($89\%\pm 1\%$) for the even (odd) parity as verified by single shot parity readout. Finally, we apply this scheme to probe the flux-dependent transition spectrum of the even or odd parity sector selectively, without any postprocessing or heralding.

When a hyperelastic hydrogel confined between two parallel glass plates begins to dry from a lateral boundary, the volume lost by evaporation is accommodated by an inward displacement of the air-hydrogel interface that induces an elastic deformation of the hydrogel. Once a critical front displacement is reached, we observe intermittent fracture events initiated by a geometric instability resulting in localized bursts at the interface. These bursts relax the stresses and irreversibly form air cavities that lead to cellular networks. We show that the spatial extent of the strain field prior to a burst, influenced by the air-hydrogel interfacial tension and the confinement of the gel, determines the characteristic size of the cavities.

Protecting coherent quantum dynamics from chaotic environment is key to realizations of fragile many-body phenomena and their applications in quantum technology. We present a general construction that embeds a desired periodic orbit into a family of nonintegrable many-body Hamiltonians, whose dynamics is otherwise chaotic. Our construction is based on time-dependent variational principle that projects quantum dynamics onto a manifold of low-entangled states, and it complements earlier approaches for embedding nonthermal eigenstates, known as quantum many-body scars, into thermalizing spectra. By designing terms that suppress “leakage” of the dynamics outside the variational manifold, we engineer families of Floquet models that host exact scarred dynamics, as we illustrate using a driven Affleck-Kennedy-Lieb-Tasaki model and a recent experimental realization of scars in a dimerized superconducting qubit chain.

The asymptotic symmetry algebra of four-dimensional Einstein gravity in the asymptotically flat context has been shown recently to be the direct sum of the Poincaré algebra and of an infinite-dimensional Abelian algebra (with central charge) that includes the Bondi-Metzner-Sachs supertranslations. This result, obtained within the Hamiltonian formalism, yields a supertranslation-invariant definition of the Lorentz generators (angular momentum and boosts). Definitions of Lorentz generators free from the “supertranslation ambiguities” have also been proposed recently at null infinity. We prove the equivalence of the two approaches for redefining the charges.

We report a measurement of the $CP$-violating parameters $C$ and $S$ in $B^0\to K_S^0{\pi }^0$ decays at Belle II using a sample of $387\times {10}^{6}B\overline{B}$ events recorded in $e^{+}{e}^{-}$ collisions at a center-of-mass energy corresponding to the $\mathrm{\Upsilon }(4S)$ resonance. These parameters are determined by fitting the proper decay-time distribution of a sample of 415 signal events. We obtain $C=-0.04_{-0.15}^{+0.14}\pm 0.05$ and $S=0.75_{-0.23}^{+0.20}\pm 0.04$, where the first uncertainties are statistical and the second are systematic.