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Understanding strongly correlated phases of matter, such as the quark-gluon plasma and neutron stars, and in particular the dynamics of such systems, for example, following a Hamiltonian quench (a sudden change in some Hamiltonian parameter, such as the strength of interparticle interactions) is a fundamental challenge in modern physics. Ultracold atomic gases are excellent quantum simulators for these problems, owing to their tunable interparticle interactions and experimentally resolvable intrinsic timescales. In particular, they provide access to the unitary regime, in which the interactions are as strong as allowed by quantum mechanics. This regime has been extensively studied in Fermi gases.sup.1,2. The less-explored unitary Bose gases.sup.3-11 offer possibilities.sup.12 such as universal physics controlled solely by the gas density.sup.13,14 and new forms of superfluidity.sup.15-17. Here, through momentum- and time-resolved studies, we explore degenerate and thermal homogeneous Bose gases quenched to unitarity. In degenerate samples, we observe universal post-quench dynamics in agreement with the emergence of a prethermal state.sup.18-24 with a universal non-zero condensed fraction.sup.22,24. In thermal gases, the dynamic and thermodynamic properties generally depend on the gas density and the temperature, but we find that they can still be expressed in terms of universal dimensionless functions. Surprisingly, we find that the total quench-induced correlation energy is independent of the gas temperature. These measurements provide quantitative benchmarks and challenges for the theory of unitary Bose gases.Degenerate and thermal Bose gases, quenched so that the interparticle interactions are as strong as allowed by quantum mechanics, exhibit dynamics that can be expressed in terms of universal functions., Author(s): Christoph Eigen [sup.1] , Jake A. P. Glidden [sup.1] , Raphael Lopes [sup.1] [sup.5] , Eric A. Cornell [sup.2] [sup.3] , Robert P. Smith [sup.1] [sup.4] , Zoran Hadzibabic [...]

Author(s): Nir Navon (corresponding author) [1]; Alexander L. Gaunt [1]; Robert P. Smith [1]; Zoran Hadzibabic [1] A central concept in the modern understanding of turbulence is the existence of [...]

Directionally tuned signalling in starburst amacrine cell (SAC) dendrites lies at the heart of the circuit that detects the direction of moving stimuli in the mammalian retina. The relative contributions of intrinsic cellular properties and network connectivity to SAC direction selectivity remain unclear. Here we present a detailed connectomic reconstruction of SAC circuitry in mouse retina and describe two previously unknown features of synapse distributions along SAC dendrites: input and output synapses are segregated, with inputs restricted to proximal dendrites; and the distribution of inhibitory inputs is fundamentally different from that observed in rabbit retina. An anatomically constrained SAC network model suggests that SAC-SAC wiring differences between mouse and rabbit retina underlie distinct contributions of synaptic inhibition to velocity and contrast tuning and receptive field structure. In particular, the model indicates that mouse connectivity enables SACs to encode lower linear velocities that account for smaller eye diameter, thereby conserving angular velocity tuning. These predictions are confirmed with calcium imaging of mouse SAC dendrites responding to directional stimuli., A thorough understanding of a neuronal circuit requires a detailed anatomical wiring diagram that includes the synaptic connectivity among the component neurons. Even ostensibly subtle connectivity differences during development or [...]