The 2024 Chengdu Symposium on Particle Physics and Cosmology: Phase Transitions, Dark Matter and Experimental Probes (CPCS 2024)

Session

Gravitational Wave

29 Sept 2024, 13:20

22. Gravitational waves induced by first-order QCD phase transitions

Jingdong Shao (University of Chinese Academy of Sciences)

29/09/2024, 13:20

We calculated the gravitational waves induced by different QCD phase transitions including in a chirality imbalanced system, in pure gluon system, in PQM, QM, and Friedberg-Lee model, and the gravitational waves can be detected by LISA, Taiji and DECIGO. We find that the values of inverse duration $\beta/H$ of these QCD phase transitions are of order
$10^4$ or $10^5$, which means the phase...

27. Bubble wall velocity and gravitational wave in the minimal left-right symmetric model

典为 王 (中国科学院大学)

29/09/2024, 13:40

The bubble wall velocity in the first order phase transition plays an important role in determining both the amplitude and the pivot frequency of stochastic gravitational wave background. In the framework of the minimal left-right symmetric model, we study the wall velocity when the first order phase transition can occur. The wall velocity can be determined by matching the distribution...

41. Estimating the uncertainty of cosmological first order phase transitions with numerical simulations of bubble nucleation

Yang Xiao (nstitute of Theoretical Physics, Chinese Academy of Scienc)

29/09/2024, 14:00

In order to study the validity of analytical formulas used in the calculation of characteristic physical quantities related to vacuum bubbles, we conduct several numerical simulations of bubble kinematics in the context of cosmological first-order phase transitions to determine potentially existing systematic uncertainties. By comparing with the analytical results, we obtain the following...

25. Impact of an early matter-dominated era on the cosmic string gravitational waves

世祺 凌

30/09/2024, 13:20

We study the stochastic gravitational wave background from cosmic strings modified by an early matter-dominated era caused by the dark matter dilution mechanism, which is commonly considered as a way to dilute the overproduced dark matter in particular scenarios. The dilutor in such a mechanism could lead to a matter-dominated era inside the conventional radiation-dominated era, affecting the...

40. The bubble wall velocity: from the local Boltzmann equations to the non-local Kadanoff-Baym equations

Dr Jiang Zhu (TDLi institution)

30/09/2024, 13:40

There are two common methods to compute the bubble wall velocity for the cosmological phase transitions: the fluid method, which analyzes the macroscopic fluid system, and the local Boltzmann equations; the microscopic method, which studies the force acting on the bubble wall by the particle interactions. However, those two methods are not consistent with each other. In this study, we present...

26. Cosmic superstrings, metastable strings and ultralight primordial black holes: from NANOGrav to LIGO

Satyabrata Datta (Nanjing Normal University)

30/09/2024, 14:00

Recent observations of nHz stochastic gravitational waves (GW) by Pulsar Timing Arrays (PTA), such as NANOGrav, have disfavored the existence of topologically stable cosmic strings. However, cosmic metastable strings and superstrings remain viable candidates. Gravitational waves from all classes of strings generally span a wide range of frequencies, which conflicts with LIGO’s non-observation...

48. Impact of local CP-odd domain in hot QCD on axionic domain-wall interpretation for NANOGrav 15-year Data

Linlin Huang (Jilin University)

30/09/2024, 14:20

We argue that the axionic domain-wall with a QCD bias may be incompatible with the NANOGrav 15-year data on a stochastic gravitational wave (GW) background, when the domain wall network collapses in the hot-QCD induced local CP-odd domain. This is due to the drastic suppression of the QCD bias set by the QCD topological susceptibility in the presence of the CP-odd domain with nonzero $\theta$...