아래와 같이 우주상수문제연구실 세미나 일정을 알려드립니다.

많은 관심과 참석바랍니다.

<일정>

■ 일시 ; 2023. 03. 10(금) 2시~

■ 장소 : 제1물리관 105호 대회의실

■ 연사 및 연제

? 초록 1 A simple model, extracted using holography, of a domain wall between a confining and a de-confining phases and its velocity

In the context of theories with a first order phase transition,

we propose a general covariant description of coexisting phases separated by

domain walls using an additional order parameter-like degree of freedom. In

the case of a holographic dual to a confining and a de-confing phases, the resulting

model extends hydrodynamics and has a simple formulation in terms

of an action and a corresponding energy-momentum tensor. The proposed

description leads to simple analytic profiles of domain walls, including the

surface tension density, which agree nicely with holographic numerical solutions.

We show that for such systems, the domain wall or bubble velocity

can be expressed in a simple way in terms of a perfect fluid hydrodynamic

formula, and thus in terms of the equation of state. We test the predictions

for various holographic domain walls.

? 초록 2 Conditional Entanglement Transfer Via Black Holes.

Hawking’s black hole evaporation process suggests that we may need to choose between quantum unitarity and other basic physical principles such as no-signaling, entanglement monogamy, and the equivalence principle. We here show that the Hawking’s quantum model for the black hole evaporation is consistent with the above fundamental principles. Our analysis does not involve exotic new physics, but rather uses standard quantum theory, general relativity, and the Einstein?Hilbert action including matter. We explicitly show that the whole state consisting of matter and radiation (in a joint superposition of different energy states) is pure at any stage of the evaporation process, including the particular case of 0 mass. Moreover, after full evaporation the state for radiation at infinity is pure and in one-to-one correspondence with the initial state forming the black hole. Thus there is no information loss upon full evaporation according to the quantum information theory. The original entanglement of the black hole matter (if any) gets transferred to the outgoing particles via a process similar to entanglement swapping, without violation of causality (as proved explicitly). On the other hand, if the initial state is a tensor product state, the entanglement of Hawking particles, present in the intermediate phase, is broken when the black hole evaporates completely. Therefore, the final state (entangled or tensor product depending on the nature of initial state) after the full black hole evaporation is pure without loss of information.