## Title: *Gravitational perturbations of rotating black holes in Lorenz gauge*
## Reporter: Yota Watanabe
## Abstract
In this journal club, I will introduce briefly a new GW dark siren method using a binary Love relation for the binary neutronstar merger. The redshift information could be extracted between the observer-frame chirp mass from gravitational waveform and the source-frame mass from the Love relatioins.
In this journal club, I will introduce the letter-size reference, which shows compact formulae to reconstruct metric perturbations around rotating black holes in the Lorenz gauge from the radiation-gauge, null-tetrad formalism.
## References
-[Arxiv:2106.06589](https://arxiv.org/abs/2106.06589)*Cosmology with Love* by *Deep Chatterjee*
-[Arxiv:2108.06344](https://arxiv.org/abs/2108.06344)*Gravitational perturbations of rotating black holes in Lorenz gauge* by *Sam R. Dolan* et al.
## Title: *Gravitational waves from resonant amplification of curvature perturbations during inflation*
## Reporter: Zhi-Zhang Peng
## Abstract
In this seminar, I will introduce my recent work about scalar-induced gravitational waves(GWs) from a single-field inflationary model with oscillatory potential. We compute the energy spectra of induced GWs produced both during inflation and in the radiation-dominated era, and we compare the differences between them.
## References
## Title: *No Inner-Horizon theorem for Anisotropic Black Holes with Charged Vector Hairs*
## Reporter: Cheng-Hu Ge
| 9.2 | 2.30 PM | 6420 | Wang-Wei Yu |
## Title: *Hubble Tension May Be a Astrophysical Problem*
## Reporter: Wang-Wei Yu
## Abstract
In this seminar, I will introduce some progress of our work. We consider a Anisotropic black holes model with charged vector hair. With the conserved charge and assumption of smoothness, we prove a no inner-horizon theorem. We also investigate asymptotic behavior of fields around the singularity and the interior dynamics.
In this seminar, I will introduce our rencent works about the local Hubble Constant. Recently, many physicists reach a consensus on that the Hubble tension is not a Cosmological problem but a astrophysical problem in local view. I'll explain how our works strength the conclusions about Hubble tension and $S_8$ tension.
