Condensed Matter Seminar: Granular and Active: Findings and behavior in many fire-ant systems

Alberto Fernandez-Nieves (U Barcelona)
- David Rittenhouse Laboratory, A4

Experiments with fire-ant columns reveal similarities and differences with granular columns. For granular columns, we will show that narrowing the column diameter can result in novel…



High Energy Theory Seminar: Emergent N=4 supersymmetry from N=1

Monica Kang (University of Pennsylvania)
- David Rittenhouse Laboratory, 3C6

I will construct 4d N=1,2 SCFTs with identical central charges a=c (without a large N limit) via the diagonal gauging of collections of non-Lagrangian Argyres–Douglas and conformal matter theories. Utilizing a…



Colloquium: Nonlinear topological photonics

Bo Zhen (University of Pennsylvania)
- David Rittenhouse Laboratory, A4

Topological photonics is a rapidly developing field, often drawing inspirations from the recent successes in electronic systems. Yet there are a few major differences between photons and electrons, leading to…



High Energy Theory Seminar: Double Scaled SYK and de Sitter Holography

Herman L. Verlinde (Princeton University)
- David Rittenhouse Laboratory, 3C6

In this talk I will describe a new and precise holographic dictionary between the SYK model in the double scaling limit and 2D de Sitter gravity.



What’s inside a black hole? Probing the interior of black holes with gravitational waves

Ramy Brustein (Ben Gurion U. of Negev)
- David Rittenhouse Laboratory, 4N12

I will present general arguments, based on fundamental physics principles, as to why we should expect a significant, horizon scale, departure from semiclassical gravity inside astrophysical black holes. Then, I will…



Astrophysics Seminar: Interstellar Interlopers and Dark Comets

Darryl Seligman (Cornell University)
- David Rittenhouse Laboratory, 4E19

In recent years, two entirely new classes of planetesimals have been discovered in the solar system: interstellar interlopers and dark comets.  These still-enigmatic objects are challenging our understanding of the…



Condensed Matter Seminar: Magnetic Chirality

Sang-Wook Cheong (Rutgers University)
- David Rittenhouse Laboratory, A4

Chirality, which arises from the breaking of mirror symmetries combined with any spatial rotations, plays a ubiquitous role in a wide range of phenomena, from the DNA…



High Energy Seminar: Nonlinear Black Hole Ringdown

Macarena Lagos (Columbia University)
- David Rittenhouse Laboratory, 3C6

Gravitational waves (GWs) offer a unique observational window into the nature of gravity. In particular, the remnant black hole formed after the merger of two compact objects emits GWs with a…



Elon Musk Public Lecture: "The Many Worlds of Quantum Mechanics"

Sean Carroll (Johns Hopkins University)
- Arch Auditorium - Arch Building (Room 208), 3601 Locust Walk

One of the great intellectual achievements of the twentieth century was the theory of quantum mechanics, according to which observational results can only be predicted probabilistically rather than with…



Condensed Matter Seminar: Multi-gap topological physics: geometrical notions, physical phases and novel response

Robert-Jan Slager (University of Cambridge)
- David Rittenhouse Laboratory, A4

I will review recent work on multi-gap topological states. These phases are characterized by topological structures that cannot be captured by advances in more conventional symmetry-based…