לוח שנה משולב

I describe the fluid/gravity dictionary, with an emphasis on horizon dynamics. I discuss black hole entropy and its extension into a local current, in GR and in higher-curvature theories. I propose a tentative, non-statistical interpretation of black hole entropy. I discuss its relation to the usual interpretation by analogy with the role of charge currents in the fluid/gravity duality.

The neurobiology of the octopus cannot be analyzed without considering its special morphology. I will start my talk by describing octopus ‘embodiment’. The “… embodied view suggests that the actual behavior emerges from the interactions dynamics of agent and environment through a continuous and dynamic interplay of physical and information processes” (Pfeifer et al., 2007). The octopus with its soft, flexible body and its large variety of active behaviors driven by a huge amount of sensory information is a special test-case for assessing this view in a biological system. I will review the motor control strategies that have evolved in the octopus to cope with this special morphology, which we are studying together with Tamar Flash. These results include a unique distribution of control and computational labor between the central and an elaborated peripheral nervous system. Continuing with this idea, I will show how a comparative, physiological analysis of learning and memory mechanisms in the octopus and cuttlefish revealed dichotomous differences in the site of plasticity in a simple fan-out fan-in network. The differences suggest the importance ‘self-organizational’ mechanisms in establishing the properties of a neural network to fit a specific embodiment.

The interfaces between two such substantially different classes of materials as inorganic metals and organic semiconductors are interesting not only from a fundamental scientific point of view, but they are also highly relevant for applications in the fields of organic and molecular electronics. Modifying the work function of an inorganic electrode with the aid of covalently bonded molecular monolayers allow tuning the charge-injection barriers into subsequently deposited organic semiconductors in organic (opto-)electronic devices and the relative alignment of the energy levels within such a layer with the electrode Fermi level dominates the charge-transport characteristics of molecular electronic devices. In this presentation, I will summarize the results of density-functional theory (DFT) calculations on self-assembled monolayers (SAMs) of organic molecules covalently grafted onto coinage-metal surfaces. After assessing the reliability of DFT to predict experimentally observable quantities, correlations between the chemical structure of the molecules constituting a SAM and the ensuing interfacial electronic structure in terms of work-function modification and relative energy-level alignment will be established. There, particular emphasis will be put on elucidating the microscopic mechanism behind Fermi-level pinning as well as on highlighting the importance of collective electrostatic effects