Past Events

  • Astronomy seminar: "Two instruments to start the new decade: HERA for 21cm cosmology and SPARCS to Monitor M-Dwarf flares affecting exoplanets"

    David Rittenhouse Laboratory, A6

    Daniel Jacobs, Arizona State University

    Two new kinds of instruments are coming of age at the end of this decade: low frequency radio telescopes and cubesats, both being used to probe questions of our cosmic origin and the nature of exoplanets. The redshifted 21 cm hydrogen line is a unique probe of the early universe. A recent putative detection by EDGES, of a larger than expected signal, raises more questions. The Hydrogen Epoch of Reionization Array (HERA) is designed to answer these questions by providing high significance detection of fluctuations in the redshift range 6 to 20.

  • High Energy Theory Seminar: "Complementarity from Identity"

    David Rittenhouse Laboratory, 2N36

    Sergei Dubovsky, New York University

  • High Energy Theory Seminar: "Analytic IR-resummation for the BAO peak"

    David Rittenhouse Laboratory, 2N36

    Matthew Lewandowsky, Institut de Physique Théorique (IPhT)

    We develop an analytic method for implementing the IR-resummation of 1404.5954, which allows one to correctly and consistently describe the imprint of baryon acoustic oscillations (BAO) on statistical observables in large-scale structure. We show that the final IR-resummed correlation function can be computed analytically without relying on numerical integration, thus allowing for an efficient and accurate use of these predictions on real data in cosmological parameter fitting.

  • High Energy Theory Seminar: "Interfaces and Topological Entanglement in Abelian Chern-Simons Theory"

    David Rittenhouse Laboratory, 4N12

    Jackson Fliss, University of Illinois, Urbana Champaign

    Starting from the condensed matter context, we consider the ground state entanglement across (possibly distinct) topological phases separated by a gapped interface.  I will explain how addressing this from the effective gauge theory illuminates some generic features of entanglement entropy in systems with gauge invariance.  In particular, we will explicitly implement the "extended Hilbert space" prescription directly in the continuum as well as highlight the unique role of the Ishibashi state in Chern-Simons entanglement.  Time permitting, I will discuss exten

  • Condensed Matter Seminar: "Soft Matter Physics of the Evolution of Multi-Cellularity"

    David Rittenhouse Laboratory, A6

    Peter Yunker, Georgia Institute of Technology

    The evolution of multicellularity set the stage for an incredible increase in the diversity and complexity of life on Earth. The increase in biological complexity associated with multi-cellularity required parallel innovation in the mechanical properties of multi-cellular bodies. Though a cursory review of any multi-cellular organism provides an appreciation of this intertwining of biological and mechanical complexity, little is known about how such mechanical properties may have evolved.

  • Astronomy seminar: "Cosmological Seed Magnetic Field from Inflation"

    David Rittenhouse Laboratory, A6

    Bharat Ratra, Kansas State University

    A cosmological magnetic field of nG strength on Mpc length scales could be the seed magnetic field needed to explain observed few microG large-scale galactic magnetic fields. I first briefly review the observational and theoretical motivations for such a seed field, two galactic magnetic field amplification models, and some non-inflationary seed field generation scenarios. I then discuss an inflation magnetic field generation model. I conclude by mentioning possible extensions of this model as well as potentially observable consequences.

  • Condensed Matter Seminar: "Physics and Applications of Mesoscopic Optics"

    David Rittenhouse Laboratory, A6

    Hui Cao, Yale University

    Random scattering of light, e.g., in paint, clouds, and biological tissue, is a common process of both fundamental interest and practical relevance. The interference of multiply scattered waves also leads to remarkable phenomena in mesoscopic physics such as Anderson localization and universal conductance fluctuations. In applications, optical scattering is the main obstacle to imaging or sending information through turbid media.

  • Experimental Particle Physics Seminar: "Exploring the landscape of electroweak supersymmetry at the LHC: a quest for a better understanding of dark matter"

    David Rittenhouse Laboratory, 3W2

    Sarah Williams, University of Cambridge

  • Special Seminar: "Searches for Supersymmetry with ATLAS"

    David Rittenhouse Laboratory, room 2C4

    Lawrence Lee, Harvard University

  • Introduction to SAXS and WAXS

    David Rittenhouse Laboratory, A6

    A new instrument for state-of-the-art X-ray scattering measurements has been installed in the LRSM in the newly renovated room 13.   The Xeuss 2.0 by XENOCS has a Cu and Mo X-ray sources, computer controlled focusing, transmission and grazing incident sample geometries, a 1M pixel Pilatus detector (2D), a smaller detector for simultaneous SAXS and WAXS, and a variety of in situ capabilities. 

    The facility will be called DEXS:  Dual Source and Environmental X-ray Scattering.