2020-11-02

UTAPwiki/セミナー/初期宇宙・相対論速報

Saddle-point solutions from gradient flow †

Fumio Uchida †

In most of the scenarios of baryogenesis, sphalerons play an important role because they violates baryon number. However, when one wants to find a sphaleron solution and estimate its energy, a difficulty sometimes arises because sphalerons are not local minima but saddle-points. Also, when one studies vacuum decay, to find bounce configurations is an important problem. In this case, one has to overcome the same difficulty because bounce solutions are saddle-points. However, a method that is intuitively understandable to find these solutions is proposed recently. In the seminar, I introduce the methodology and prove its validity, mainly following [1].

References:
[1] S. Chigusa, T. Moroi, and Y.Shoji, PLB800, 135115 (2020)
[2] R. Sato, PRD101, 016012 (2020); Y. Hamada, and K. Kikuchi, PRD101, 096014 (2020).