Pulsar timing arrays (PTAs) consisting of widely   distributed and well-timed millisecond pulsars can serve as a galactic-scale detector to measure gravitational waves. With the same data acquired for PTAs, we propose to develop pulsar polarization arrays (PPAs), to explore astrophysics and fundamental physics. As in the case of PTAs, PPAs are best suited to reveal temporal and spatial correlations at large scales that are hard to   mimic by local noise. To demonstrate the physical potential of PPAs, we consider detection of ultralight axionlike dark matter (ALDM), through cosmic birefringence induced by its Chern-Simons coupling. Because of its tiny mass, the ultralight ALDM can be generated as a Bose-Einstein condensate, characterized by a strong wave nature. Incorporating both temporal and spatial correlations of the signal, we show that the projected PPA limits on ALDM form a great complementarity with the existing bounds.

报告人简介: 

任婧，中国科学院高能物理研究所理论室副研究员。2014年于清华大学获得博士学位，2014年至2018年在加拿大多伦多大学物理系从事博士后研究，2018年入职高能所。主要从事粒子物理、引力及其交叉方向研究，探索超出粒子物理标准模型和广义相对论的新物理。近年来的研究兴趣集中在黑洞和量子引力效应、引力波回声探测、暗物质理论及唯象学研究等方面。

邀请人:

王少江 副研究员