Host: Prof. David Ballantyne

Title: Fast Radio Bursts: What Millisecond Flashes Reveal About Neutron Stars, Space Plasma, and Cosmology

Abstract:
Fast radio bursts are among the most luminous coherent radio signals in the Universe, releasing enormous radio luminosities on millisecond timescales. Their discovery has opened a new window onto highly magnetized neutron stars, relativistic plasma physics, and the distribution of matter across cosmic distances. In this talk I will describe how FRBs have evolved from a phenomenological mystery into a quantitative probe of compact-object engines and intervening plasma. I will discuss the evidence connecting at least some FRBs to highly magnetized neutron stars (magnetars), the constraints imposed by energetics, repetition, burst durations, host environments, and multiwavelength limits, and the theoretical challenges of producing coherent emission with such high brightness temperatures. I will then show how the same signals can be used as backlights for cosmic plasma, including the intergalactic medium and small-scale plasma structures near the source. I will argue that FRBs are emerging as a bridge between neutron-star magnetospheres, relativistic outflows, and cosmology.