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Abstract Valdivia Bank (VB) is an oceanic plateau in the South Atlantic that formed from hotspot‐ridge volcanism during the Late Cretaceous at the Mid‐Atlantic Ridge (MAR). It is part of Walvis Ridge (WR), a quasi‐linear seamount chain extending from offshore Namibia to Tristan da Cunha and Gough Islands. To understand Valdivia Bank evolution, we interpret the seismic stratigraphy from multichannel seismic data paired with coring results from International Ocean Discovery Program (IODP) Expedition 391, which recovered mostly pelagic nannofossil ooze and chalks. The seismic section can be divided into three seismic units (SU), a lower transparent interval which is faulted and conforms to basement, a middle, moderate to high amplitude interval which is thick in local depocenters such as rifts, and an upper, subparallel transparent interval. Notable features include regional unconformities, dipping clinoforms, mass transport and contourite deposits, and volcanic structures. Additionally, three infilled rifts are observed across the plateau. Our analysis implies that following a period of sedimentation in the Campanian, the edifice was faulted through the Paleocene, coinciding with a South Atlantic tectonic reorganization. Local depocenters formed as a result of rifting. Subsequently, the plateau experienced thermal rejuvenation and regional uplift during the Eocene. Volcanic mounds were emplaced atop Cretaceous sediments and intrusives were emplaced within the sediments. During the Cenozoic, sedimentation was punctuated, likely in response to changes in the carbonate compensation depth and bottom current intensification. VB sedimentation was complex and largely influenced by the paleoceanographic context of the plateau, as well as thermal rejuvenation and tectonism. 

This document summarizes the efforts of the EMMI Rapid Reaction Task Force on “Suppression and (re)generation of quarkonium in heavy-ion collisions at the LHC”, centered around their 2019 and 2022 meetings. It provides a review of existing experimental results and theoretical approaches, including lattice QCD calculations and semiclassical and quantum approaches for the dynamical evolution of quarkonia in the quark-gluon plasma as probed in high-energy heavy-ion collisions. The key ingredients of the transport models are itemized to facilitate comparisons of calculated quantities such as reaction rates, binding energies, and nuclear modification factors. A diagnostic assessment of the various results is attempted and coupled with an outlook for the future. 

We demonstrate a method to obtain homogeneous atom-cavity coupling by selecting and keeping 87Rb atoms that are near maximally coupled to the cavity's standing-wave mode. We select atoms by imposing an AC Stark shift on the ground state hyperfine microwave transition frequency with light injected into the cavity. We then induce a spin flip with microwaves that are resonant for atoms that are near maximally coupled to the cavity mode of interest, after which, we use radiation pressure forces to remove from the cavity all the atoms in the initial spin state. Achieving greater homogeneity in the atom-cavity coupling will potentially enhance entanglement generation, intracavity driving of atomic transitions, cavity-optomechanics, and quantum simulations. This approach can easily be extended to other atomic species with microwave or optical transitions. 

We study the problem of synthesizing a controller that maximizes the entropy of a partially observable Markov decision process (POMDP) subject to a constraint on the expected total reward. Such a controller minimizes the predictability of an agent’s trajectories to an outside observer while guaranteeing the completion of a task expressed by a reward function. Focusing on finite-state controllers (FSCs) with deterministic memory transitions, we show that the maximum entropy of a POMDP is lower bounded by the maximum entropy of the parameteric Markov chain (pMC) induced by such FSCs. This relationship allows us to recast the entropy maximization problem as a so-called parameter synthesis problem for the induced pMC. We then present an algorithm to synthesize an FSC that locally maximizes the entropy of a POMDP over FSCs with the same number of memory states. In a numerical example, we highlight the benefit of using an entropy-maximizing FSC compared with an FSC that simply finds a feasible policy for accomplishing a task. 

We provide a quantitative analysis of the spontaneous recombination time in the quantum well (QW) of a transistor laser (TL) that shows that owing to the heavy doping in the base of the transistor, Auger recombination is responsible for the short carrier lifetime and low quantum efficiency of the device. By taking advantage of the QW location close to the collector in the TL three-terminal configuration, we devise a new turn-off mechanism that results in quick electron tunneling through the QW barrier by applying a high base-collector reverse bias to deplete the QW and suppress further recombination. For practical base-collector reverse bias, tunneling time from the QW is on the order of 10th of picosecond, which with a lighter base doping density would simultaneously achieve a fast TL turn-off response, while reducing Auger recombination. 

Abstract We present a catalog of 315 protostellar outflow candidates detected in SiOJ= 5 − 4 in the ALMA-IMF Large Program, observed with ∼2000 au spatial resolution, 0.339 km s⁻¹velocity resolution, and 2–12 mJy beam⁻¹(0.18–0.8 K) sensitivity. We find median outflow masses, momenta, and kinetic energies of ∼0.3M_⊙, 4M_⊙km s⁻¹, and 10⁴⁵erg, respectively. Median outflow lifetimes are 6000 yr, yielding median mass, momentum, and energy rates of $\dot{M}$= 10^−4.4M_⊙yr⁻¹, $\dot{P}$= 10^−3.2M_⊙km s⁻¹yr⁻¹, and $\dot{E}$= 1L_⊙. We analyze these outflow properties in the aggregate in each field. We find correlations between field-aggregated SiO outflow properties and total mass in cores (∼3σ–5σ), and no correlations above 3σwith clump mass, clump luminosity, or clump luminosity-to-mass ratio. We perform a linear regression analysis and find that the correlation between field-aggregated outflow mass and total clump mass—which has been previously described in the literature—may actually be mediated by the relationship between outflow mass and total mass in cores. We also find that the most massive SiO outflow in each field is typically responsible for only 15%–30% of the total outflow mass (60% upper limit). Our data agree well with the established mechanical force−bolometric luminosity relationship in the literature, and our data extend this relationship up toL≥ 10⁶L_⊙and $\dot{P}$≥ 1M_⊙km s⁻¹yr⁻¹. Our lack of correlation with clumpL/Mis inconsistent with models of protocluster formation in which all protostars start forming at the same time. 

We develop a new boundary integral method for solving the coupled electro- and hydrodynamics of vesicle suspensions in Stokes flow. This relies on a well-conditioned boundary integral equation formulation for the leaky-dielectric model describing the electric response of the vesicles and an efficient numerical solver capable of handling highly deflated vesicles. Our method is applied to explore vesicle electrohydrodynamics in three cases. First, we study the classical prolate–oblate–prolate transition dynamics observed upon application of a uniform DC electric field. We discover that, in contrast to the squaring previously found with nearly spherical vesicles, highly deflated vesicles tend to form buds. Second, we illustrate the capabilities of the method by quantifying the electrorheology of a dilute vesicle suspension. Finally, we investigate the pairwise interactions of vesicles and find three different responses when the key parameters are varied: (i) chain formation, where they self-assemble to form a chain that is aligned along the field direction; (ii) circulatory motion, where they rotate about each other; (iii) oscillatory motion, where they form a chain but oscillate about each other. The last two are unique to vesicles and are not observed in the case of other soft particle suspensions such as drops. 

Abstract Sawtooth Wave Adiabatic Passage (SWAP) laser cooling was recently demonstrated using a narrow-linewidth single-photon optical transition in atomic strontium and may prove useful for cooling other atoms and molecules. However, many atoms and molecules lack the appropriate narrow optical transition. Here we use such an atom,⁸⁷Rb, to demonstrate that two-photon Raman transitions with arbitrarily-tunable linewidths can be used to achieve 1D SWAP cooling without significantly populating the intermediate excited state. Unlike SWAP cooling on a narrow transition, Raman SWAP cooling allows for a final 1D temperature well below the Doppler cooling limit (here, 25 times lower); and the effective excited state decay rate can be modified in time, presenting another degree of freedom during the cooling process. We also develop a generic model for Raman Landau–Zener transitions in the presence of small residual free-space scattering for future applications of SWAP cooling in other atoms or molecules. 

Abstract We report the observation of gravitational waves from two binary black hole coalescences during the fourth observing run of the LIGO–Virgo–KAGRA detector network, GW241011 and GW241110. The sources of these two signals are characterized by rapid and precisely measured primary spins, nonnegligible spin–orbit misalignment, and unequal mass ratios between their constituent black holes. These properties are characteristic of binaries in which the more massive object was itself formed from a previous binary black hole merger and suggest that the sources of GW241011 and GW241110 may have formed in dense stellar environments in which repeated mergers can take place. As the third-loudest gravitational-wave event published to date, with a median network signal-to-noise ratio of 36.0, GW241011 furthermore yields stringent constraints on the Kerr nature of black holes, the multipolar structure of gravitational-wave generation, and the existence of ultralight bosons within the mass range 10⁻¹³–10⁻¹²eV.