Astrophysics

Astrophysical black holes are surrounded by accretion disks, jets, and coronae consisting of magnetized, (near)-collisionless relativistic plasma. They produce observable high-energy radiation and it is currently unclear where and how this emission...

The histories of physics and astronomy at Penn will be presented primarily through the lives of prominent individuals, culminating in the 1994 merger of the Physics and Astronomy Departments. We will meet David Rittenhouse, who observed the transit...

What role should scientists play in public policy nationally or locally? Do we have any more of an obligation than others to participate in the political process? While technical issues are clearly within the natural purview of a scientist, is a...

Abstract: While the experimental program to detect ever lighter dark matter is proceeding full steam ahead, the theory of such light, detectable dark matter is at a crossroads. I will detail two examples of sub-GeV hadrophilic dark matter models...

Abstract: Holography relates quantum many-body systems to gravitational theories. Quantum entanglement plays a key role to explain how the spacetime geometries in gravity emerge from quantum systems. A new class of holography can be found by...

The fast solar wind that fills the heliosphere originates from deep within regions of open magnetic field on the Sun called ‘coronal holes’. The energy source responsible for accelerating the plasma is widely debated, however there is evidence that...

The Bahcall Lunch follows the astrophysics colloquium lecture. 

For more than a decade, enigmatic extragalactic flashes called fast radio bursts (FRBs) have defied a definitive explanation for their origin. In addition, the unique properties of FRBs make them promising probes of both cosmology and the...

Each week, we hold a relatively informal seminar/discussion series with an emphasis on extra-galactic and large-scale structure astrophysics.

During Galread a leader/visitor presents a recent paper to the discussion group. The PDF of the paper is...