## Title: *Holographic Reconstruction of Spacetime and Renormalization in the AdS/CFT Correspondence*
## Reporter: Shou-Cheng Wang
| 6.1 | 10.00 AM | 6420 | Teng Ji |
## Title: *Transverse Goldstone mode in holographic fluids with broken translations*
## Reporter: Teng Ji
## Abstract
I will review an old classic literature and learn some fundamental aspects about AdS/CFT Correspondence. This paper developed a systematic method for renormalizing the AdS/CFT prescription for computing correlation functions. This method can also be viewed as providing a holographic reconstruction of the bulk spacetime metric and of bulk fields on this spacetime, out of conformal field theory data.
In this talk, I will introduce transverse goldstone mode in holographic fluids with broken translations. In absence of momentum relaxation, the authors find that there exist two gapless modes in the transverse channel, one of which is purely diffusive and the other is non-dynamical due to the lack of rigidity. Switching on an external source which breaks the translations explicitly but weakly, the would-be gapless modes acquire a tiny mass gap. Finally, in the strong momentum relaxation regime, they find a (pseudo-)diffusive-to-sound crossover that is set by a momentum gap
## References
-[arXiv:hep-th/0002230](https://arxiv.org/abs/hep-th/0002230)*Holographic Reconstruction of Spacetime and Renormalization in the AdS/CFT Correspondence* by *Sebastian de Haro* et. al.
-[arXiv:2202.05437](https://arxiv.org/abs/2202.05437)*Transverse Goldstone mode in holographic fluids with broken translations* by *Yuan-Yuan Zhong* and *Wei-Jia Li*.
## Interesting papers in this week
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@@ -40,34 +40,34 @@ I will review an old classic literature and learn some fundamental aspects about
## Title: *Microlensing Constraints on Dressed Primordial Black Holes*
## Reporter: Tan Chen
| 6.1 | 2.30 PM | 6420 | Zi-Yan Yuwen |
## Title: *Energy Budget during Phase Transition Beyond the Bag Equation of State*
## Reporter: Zi-Yan Yuwen
## Abstract
Dark matter is one of the most essential ingredients in the standard model of cosmic structure formation, but its nature is not yet known. Primordial black holes are alternative viable candidate of Dark matter. There are various attempts at constraining PBHs over almost twenty orders of magnitudes in their mass scales. Microlensing is one of the most robust, powerful method among them. However, all these constraints obtained from microlensing only consider PBHs without halo, which inspires us to reconsider the constraints on PBHs using dressed black holes model.
## References
First order phase transition (FOPT) is studied recent years for its shading lights on many important and interesting phenomena in the early universe. And Especially, the energy budget is strongly connected with SGWB from FOPT. I will present our recent work on the energy budget during FOPT using a method which can go beyond bag equation-of-state (EOS) despite the particle physics model one uses. We show that after considering the sub-leading-order contribution from EOS, the efficiency factor inevitably decreases, which leads to a decreasing on Ω_gw. We also find a lower bound for phase transitionstrength factor coming from a physical requirement on junction condition.
<!-- ## References -->
<!-- - [arXiv:2203.13286](https://arxiv.org/abs/2203.13286) *Preheating in Palatini Higgs inflation on the lattice* by *Frédéric Dux* and *Adrien Florio*. -->