Past Events

Astro Seminar: "Investigation of Keplerlike Laws of Galactic Dynamics In Dispersionsupported Spherical Galaxies and Test of Dark Matter and Modified Gravity Theories"
April 5, 2017  2:00 pm
David Rittenhouse Laboratory, A4
KyuHyun Chae (Sejong University)
Whether dynamical systems such as galaxies, galaxy clusters and the universe itself are controlled by Einstein’s theory of gravity in conjunction with yettobeidentified dark matter/energy or alternatively by modified gravity is an outstanding current problem of astrophysics and fundamental physics.

High Energy Seminar: "Black Holes in Massive Gravity: TimeDependent Solutions"
April 5, 2017  12:00 pm  1:00 pm
DRL 2N36
Rachel A. Rosen (Columbia University)
When starting with a static, sphericallysymmetric ansatz, there are two types of black hole solutions in massive gravity: (i) exact Schwarzschild solutions which exhibit no Yukawa suppression at large distances and (ii) solutions which contain coordinateinvariant singularities at the horizon. In this talk, I will present new black hole solutions which have a nonsingular horizon and can potentially be matched to Yukawa asymptotics at large distances. These solutions recover Schwarzschild black holes in the limit of zero graviton mass and are thus observationally viable.

MathBio seminar: " The mathematical foundation of a landscape theory for living matters and life"
April 3, 2017  4:00 pm  5:00 pm
Carolyn Lynch Laboratory, 318
Hong Qian (University of Washington)
The physicists' notion of energy is derived from Newtonian mechanics. The theory of thermodynamics is developed based on that notion, and the realization of mechanical energy dissipation in terms of heat. Since the work of L. Boltzmann, who trusted that atoms were real as early as in 1884, the heat became intimately related to the stochastic motion of the invisible atoms and molecules.

High Energy Seminar: "Modular spacetime and Metastring theory"
April 3, 2017  2:00 pm  3:00 pm
DRL 2N36
Djordje Minic (Virginia Tech)
In this talk we review our recent work on metastring theory and its habitat, a new form of quantum spacetime, called modular spacetime. We emphasize that the geometry underlying modular spacetime, i.e. the background geometry ofmetastring theory, is also the geometry underlying generic representations of quantum theory as formulated in terms of Aharonov's modular variables. Thus the metastring sheds light on the foundations of quantum theory, andit represents a new formulation of string theory and quantum gravity based on the principle of relative locality. 
Dissertation Defense: "Supernova Cosmology and How to Talk About It: New Approaches to Cosmological Parameter Inference with Type Ia Supernovae and an Assessment of the Education and Public Outreach Program of The Dark Energy Survey"
April 3, 2017  2:00 pm
DRL 3W2
Rachael CaneWolf (UPenn)

Condensed Matter Seminar: "Atomic Crystals with New Twists"
March 29, 2017  4:00 pm  5:00 pm
David Rittenhouse Laboratory, A4
Jiwoong Park, Cornell University
Chiral materials possess left and righthanded counterparts linked by mirror symmetry, with applications in physics, chemistry and biology. In atomic crystals such as graphene, chiral symmetry emerges naturally as a consequence of the honeycomb lattice. In this talk, I will discuss two recent studies where the interaction between graphene and another surface breaks this chiral symmetry. The first example is chiral twisted bilayer graphene, a twoatomthick chiral film, with giant circular dicrhoism.

Astro Seminar: "LargeScale Structure Tests of Galaxy Formation and Modified Gravity"
March 29, 2017  2:00 pm  3:00 pm
David Rittenhouse Laboratory, A4
Ying Zu (Ohio State University).
I will present novel tests of galaxy formation theories and the nature of gravity, using largescale structure measurements from the Sloan Digital Sky Survey (SDSS). I will first introduce the iHOD model, a probabilistic framework for mapping galaxy properties to their underlying dark matter halos. By modelling the color dependence of galaxy clustering and weak gravitational lensing, iHOD reveals a surprisingly simple picture for "galaxy quenching", i.e., the cessation of starformation activities within galaxies.

*Special* High Energy Seminar: "Monopoleantimonopole Creation and Other Numerical Studies"
March 28, 2017  11:00 am
DRL 4N12
Tanmay Vachaspati (Arizona State University)
I will describe magnetic monopoles, their properties, and recent numerical work on their creation from particles.

High Energy Theory: "TBA"
March 27, 2017  2:00 pm
TBA
Tom Hartman (Cornell University)

Advances in Biomedical Optics Seminar: "Optical Diagnostics for Improved Pancreatic Disease Detection"
March 23, 2017  12:00 pm
Donner Auditorium, Basement, Donner Building, 3400 Spruce St.
MaryAnn Mycek (University of Michigan)
Pizza will be served at 11:45am.
These seminars are supported by the Biomedical Imaging and Spectroscopy Laboratory, the Center for Magnetic Resonance and Optical Imaging, the Department of Radiology and the Department of Physics and Astronomy at the University of Pennsylvania.
*Organizers: Wesley Baker, Jeff Cochran, Bryan Chong, Tiffany Ko, and Arjun Yodh,
*Contact: Wesley Baker