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Gravitational Waves and Fundamental Physics with Pulsar Timing Arrays

03/14 2023 Seminar
  • Title Gravitational Waves and Fundamental Physics with Pulsar Timing Arrays
  • Speaker Siyuan Chen (KIAA-PKU)
  • Date 14:30 Mar. 14, 2023
  • Venue 6620 ITP South Building Tencent No.:100-934-042 https://meeting.tencent.com/dm/QL9yaBYExXCZ
  • Abstract
    Pulsar Timing Arrays (PTAs) search for nHz gravitational waves by timing the radio signals from a network of stable millisecond pulsars and looking for a spatially correlated common signal in the data set. We expect to find a gravitational wave background (GWB) first, followed by possible individual sources. PTAs have reported the finding of a spectrally similar but spatially uncorrelated signal in various data sets, namely North American Nanohertz Observatory for Gravitational waves (NANOGrav), Australian Parkes PTA, European PTA, together with the Indian PTA they form the International PTA. We hope to deepen collaboration with Chinese and South African PTA colleagues.
    I will present results from the different PTAs on the search for a GWB. All PTAs report consistent results of a common signal with a nominal amplitude of 2-3e-15, but no characteristic spatial correlation required for a GWB. This putative signal has been tested against both cosmological and astrophysical sources for a GWB and helped to put constraints for various theories. We are working in the four PTA collaborations to collect and analyze the most recent data sets in a coordinated process, including the supervision of an external Detection Committee under the guidance of the IPTA. We hope to have exciting results to present by the end of this year. These new data sets will form the basis for the next IPTA DR3 combination in the coming year.