Pulsar timing array observations as possible hints for nonsingular cosmology

The European Physical Journal C, vol. 83

Abstract

Abstract Recent pulsar timing array (PTA) experiments have reported strong evidence of the stochastic gravitational wave background (SGWB). If interpreted as primordial gravitational waves (GWs), the signal favors a strongly blue-tilted spectrum. Consequently, the nonsingular cosmology, which is able to predict a strongly blue-tilted GW spectrum with $$n_T \simeq 2$$ n T ≃ 2 on certain scales, offers a potential explanation for the observed SGWB signal. In this paper, we present a Genesis-inflation model capable of explaining the SGWB signal observed by the PTA collaborations while also overcoming the initial singularity problem associated with the inflationary cosmology. Furthermore, our model predicts distinctive features in the SGWB spectrum, which might be examined by forthcoming space-based gravitational wave experiments.

Authors 3

1. Mian Zhu

   Jagiellonian University · Zhengzhou University

   Affiliation as printed

   Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, 30-348, Kraków, Poland

   School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, Henan, China

2. Gen Ye corresponding Aachen Institute Lorentz

   Leiden University

   Affiliation as printed

   Institute Lorentz, Leiden University, PO Box 9506, 2300 RA, Leiden, The Netherlands

3. Yong Cai corresponding

   Zhengzhou University

   Affiliation as printed

   School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, Henan, China