Tensor perturbations from bounce inflation scenario in f(Q)gravity  

作　　者：Kun Hu Tanmoy Paul Taotao Qiu 

机构地区：[1]Institute of Astrophysics,Central China Normal University,Wuhan 430079,China [2]School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China [3]National Institute of Technology Jamshedpur,Department of Physics,Jamshedpur 831014,India

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第2期78-92,共15页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2021YFC2203100);the National Natrual Science Foundation of China(Grant No.11875141)。

摘　　要：In this paper,we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity,namely f(Q)theory,and investigate the tensor perturbations therein.As is well-known,the tensor perturbations generated in the very early Universe(inflation and pre-inflation regions)can account for the primordial gravitational waves(PGWs)that are to be detected by the next generation of GW experiments.We discuss the stability condition of the tensor perturbations in the bounce inflation process and investigate in detail the evolution of the perturbation variable.The general form of the tensor power spectrum is obtained both for large as well as small scale modes.As a result,we show both kinds of modes(short or long wavelength modes),and the tensor spectrum may get a positive tilt in the parametric range where the tensor perturbation proves to be stable—this interestingly hints an enhancement of gravitational waves’amplitude in the background of the f(Q)bounce-inflation scenario.Moreover,we study the LQC-like scenario as a specific case of our model,in which,the primordial tensor power spectrum turns out to be nearly scale-invariant on both small and large scales.

关 键 词：bounce cosmology modified gravity cosmological perturbations 

分 类 号：P159[天文地球—天文学]