AP/Physics Colloquium

The NANOGrav 12.5-Year Data Set: Knocking at the Gravitational Wave Door

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Speaker
Maura McLaughlin (West Virginia University) via zoom

Millisecond pulsars are rapidly rotating neutron stars with phenomenal rotational stability. The NANOGrav collaboration monitors an array of about 80 of these cosmic clocks in order to detect perturbations due to gravitational waves at nanohertz frequencies. These gravitational waves will most likely result from an ensemble of supermassive black hole binaries. Their detection and subsequent study will offer unique insights into galaxy growth and evolution over cosmic time.

Frontiers in Cosmic Magnetism and in Many-Body Physics

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Speaker
Susan Clark & Vedika Khemani (Stanford University) via zoom

Galaxies like our Milky Way host large-scale, weak magnetic fields. The interstellar magnetic field affects a wide range of physics, from cosmic ray propagation to star formation. The magnetic interstellar medium is also a formidable foreground for experimental cosmology, particularly for the quest to find signatures of inflation in the polarized cosmic microwave background.