Machine Learning Group Meeting Room: Classroom Machine Learning Group Meeting Description: Please email Gabriella Contardo to join if interested in the nuts and bolts of ML x Astrophysics.

Stars and Exoplanets Meeting Room: Classroom Researchers in the NYC area working on the Milky Way, stellar astrophysics, and extra-solar planets gather to discuss projects in progress and scientific issues of mutual interest. This meeting is open.

Gravitational Waves Group Meeting Room: Classroom

SF Lecture: Mark Schnitzer Room: Classroom Gerald D. Fischbach Auditorium - 160 Fifth Avenue at 21st Street, 2nd floor FUNDAMENTAL BOUNDS ON THE FIDELITY OF SENSORY CORTICAL CODING Lecture 5:00 - 6:15 PM Perception is limited by the information that the brain can extract from the noisy dynamics of sensory neurons. In this lecture, Mark Schnitzer will present a new microscope to monitor neural activity across the primary visual cortex and analyses to quantify the information conveyed by large neural ensembles. The data reveal limitations on the accuracy of sensory cortical coding due to correlated fluctuations in neural dynamics. Seminal experiments published three decades ago suggested that correlated activity fluctuations within sensory cortical neural ensembles are what limits their coding accuracy. However, without concurrent recordings from thousands of cortical neurons with shared sensory inputs, it has remained unknown whether correlated noise limits coding fidelity. Schnitzer and colleagues found that, in the mouse visual cortex, correlated noise constrained signaling for ensembles of 800–1,300 neurons. Moreover, neural ensemble visual signals were perpendicular to the largest noise mode, which, therefore, did not limit coding fidelity. The information-limiting noise modes were approximately 10 times smaller and concordant with mouse visual acuity. Cortical design principles appear to enhance coding accuracy by restricting roughly 90 percent of noise fluctuations to modes that do not limit signaling fidelity, whereas much weaker correlated noise modes bound sensory discrimination. Schnitzer is an HHMI Investigator and a professor at Stanford University’s applied physics and biology departments. His work has focused on the innovation and use of optical imaging technologies for understanding how large neural ensembles control animal behavior. His lab has invented several technologies now commercially available, including tiny microscopes that are small enough to be mounted on the head of a freely behaving mouse and that are currently used by more than 500 labs worldwide. Registration is required for this free webinar. Further instructions and access to join the webinar will be sent to all registrants upon sign up.

Compact Objects Group Meeting Room: Classroom

Staff Meeting Room: Classroom

Galaxy Formation Group Meeting Room: Classroom Galaxy Formation Group Meeting Description: By Invitation Only. Email rachel somerville if you would like to participate.

Astronomical Data Internal Group Meeting Room: Classroom Astronomical Data Internal Group Meeting Description: Group members meet for workshop projects. Email Hogg if you’d like to participate.

Planet Formation Group Meeting Room: Classroom

CCA Colloquium: Stephon Alexander Room: Classroom The Story of a Halo: Chern-Simons Theory, Cosmic Inflation and Dark Genesis All matter, visible and dark, had to originate from some mysterious event in the early universe-baryogenesis and dark-genesis. This necessary physics goes beyond our standard cosmology and the standard model of particle physics. In this colloquium, I provide a pedagogical introduction to cosmic inflation, baryogenesis and argue the necessity of Chern-Simons theory in collaboration with the quantum dynamics of cosmic inflation (but not limited to it) to explain the coincidence between the density of dark and visible matter. A surprise regarding quantum coherence in halos awaits as a result.