### Members profile（10th）

##### ● Tomonori UGAJIN Assistant Professor

Research Interests:
Theoretical physics, high energy theory

Research Topic:
Applications of quantum information theory to fundamental physics

Host Department:
Yukawa Institute for Theoretical Physics

Previous Affiliation:
University of Pennsylvania

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Short Introduction

Gravity is one of the physical phenomena that we are very familiar with. At the cosmological scale, dynamics of gravity is described by distortion of spacetime geometry, according to Einstein’s theory of general relativity. However, physical law that governs the behavior of gravity at very tiny scale which is comparable to the size of elementary particles (quantum gravity) is yet to be found. A suggestive hint toward this theory is the fact that a black hole has entropy proportional to the area of its event horizon.

This immediately implies the geometric properties of our macroscopic world are somehow emergent from the information theoretic properties of the microscopic world. I have been trying to understand how this emergence of spacetime as well as gravity, happens in holographic principle (especially in AdS/CFT correspondence), which is considered as a way to define a quantum theory of gravity. In doing so, relative entropy, one of the central concepts in quantum information theory, plays a key role. In addition to this, I am also interested in applications of relative entropy to other fields of theoretical physics such as condensed matter theory and non equilibrium physics.

Introduction Research(PDF)

Research activity status (external page)

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