Title: Leptonic CP Violation in Neutrino Oscillations

Speaker: Dr. Shun Zhou （周顺）(KTH, Stockholm)

Time: 3:00PM, Mar. 6th (Thursday)

Place: Theoretical Physics Division，319

Seminar2

Title: A speculation on the nature of black hole horizon

Speaker: Dr. Jianwei Mei （梅健伟）(华中科技大学)

Time: 4:00PM, Mar. 6th (Thursday)

Place: Theoretical Physics Division，319

Abstract: In the light of the recent debate on black hole firewalls, we study the possibility that the black hole horizon is a physical boundary to the spacetime. The dynamics of such a boundary is naturally governed by the Gibbons-Hawking-York boundary term. Using the Kerr black hole as an example we derive an effective action that describes, in the large wave number limit, a massless Klein-Gordon field living on the average location of the boundary. Complete solutions can be found in the small rotation limit of the black hole. The formulation suggests that the boundary can be treated in the same way as any other matter contributions. In particular, the angular momentum of the boundary matches exactly with that of the black hole, suggesting an interesting possibility that all charges (including the entropy) of the black hole are carried by the boundary. Using this as input, we derive predictions on the Planck scale properties of the boundary.