Events List

DateEvent TypeSpeaker
04/01/2025Astro SeminarBart Ripperda [ + ]
04/01/2025Informal Astro TalkRaagini Patki [ + ]
04/02/2025HEP Journal Club [ + ]
04/02/2025HEP SeminarCsaba Csaki [ + ]
04/03/2025Physics Dept ColloquiumAlessandra Buonanno [ + ]
04/04/2025Special SeminarDalimil Mazac [ + ]
04/04/2025Hep-Th Discussion SessionCalkins [ + ]
04/08/2025Astro SeminarMagdalena Siwek [ + ]
04/09/2025HEP Journal Club [ + ]
04/09/2025HEP SeminarLorenzo Ricci [ + ]
04/09/2025Cosmic Happy HourCammie Norton [ + ]
04/10/2025Physics Dept ColloquiumJesse Thaler [ + ]
04/11/2025Hep-Th Discussion SessionCalkins [ + ]
04/14/2025Special SeminarMisha Shaposhnikov [ + ]
04/15/2025Astro SeminarJulien Lavalle [ + ]
04/16/2025HEP Journal Club [ + ]
04/16/2025HEP SeminarMichael Baker [ + ]
04/18/2025Hep-Th Discussion SessionCalkins [ + ]
04/21/2025CCPP Brown BagMarius Kongsore [ + ]
04/21/2025Informal HEP TalkNat Levine [ + ]
04/22/2025Astro SeminarGabriela Sato-Polito [ -- ]

Title: Where are the supermassive black holes measured by PTAs?
Abstract: Pulsar timing arrays (PTAs) consist of a set of regularly monitored millisecond pulsars with extremely stable rotational periods. The arrival time of pulses can be altered by the passage of gravitational waves (GWs) between them and the Earth, thus serving as a galaxy-wide GW detector. Evidence for the first detection of low-frequency (~nHz) gravitational waves has recently been reported across multiple PTA collaborations, opening a new observational window into the Universe. Although the origin of the GW signal is yet to be determined, the dominant sources are expected to be inspiralling supermassive black holes. I will discuss what we are learning from mapping the nano-hertz GW sky, focusing on a recent work in which we compare the GW detections by PTAs with the expected signal implied by existing electromagnetic observations in a simple but robust manner. We highlight that there is a simple upper limit to the GWB amplitude and that the currently measured GW amplitude is somewhat larger than expected. I will then show that additional information regarding the typical number of sources contributing to the background can already be inferred from current PTA data. (2:00 PM - 3:15 PM, 726 Broadway, 940, CCPP Seminar)
04/23/2025HEP Journal Club [ + ]
04/23/2025HEP SeminarGiovanni Villadoro [ + ]
04/25/2025Informal HEP TalkWeiguang Cao [ + ]
04/25/2025Hep-Th Discussion SessionCalkins [ + ]
04/28/2025CCPP Brown BagMarcus DuPont [ + ]
04/29/2025Astro SeminarRisa Wechsler [ + ]
04/29/2025Oral DefenseJoan La Madrid [ + ]
04/30/2025Oral DefenseCalvin Chen [ + ]
04/30/2025HEP SeminarHarikrishnan Ramani [ + ]
04/30/2025HEP Journal Club [ + ]