FY2018 Annual Report

Quantum Gravity Unit
Assistant Professor Yasha Neiman

 

Abstract

Our work consisted of several strands. Yasha Neiman with students worked on higher-spin holography in de Sitter space. LinQing Chen worked on asymptotic symmetries of quantum electrodynamics in Minkowski space. Henry Stoltenberg worked on complexity of open quantum systems. Tomonori Ugajin worked on relative entropy in conformal field theories and holography.

1. Staff

  • Dr. LinQing Chen, Postdoctoral Scholar
  • Dr. Henry Stoltenberg, Postdoctoral Scholar
  • Dr. Tomonori Ugajin, Postdoctoral Scholar
  • Dr. Vyacheslav Lysov, Postdoctoral Scholar
  • Dr. Sudip Ghosh, Postdoctoral Scholar

2. Collaborations

Chaos and relative entropy in conformal field theory and holography

  • Description: This resulted in a joint paper in May 2018.
  • Type of collaboration: Joint research
  • Researchers:
    • Dr. Tomonori Ugajin, OIST
    • Dr. Yuya Nakagawa (then Ph.D. student), Tokyo University
    • Dr. Gabor Sarosi, University of Pennsylvania and Vrije Universiteit Brussel

3. Activities and Findings

3.1 Penrose transform in higher-spin gravity and its holographic dual

Yasha Neiman completed his work on establishing a twistor language for higher-spin holography. Holographic duality is a non-local relation between radically different descriptions of the same theory, formulated in terms of two different spacetimes. My work has established, for the first time and in a simple example, the existence of a third, intermediate, formulation, which doesn’t rely on spacetime at all, and puts the two sides of the duality on a common foundation. This work was featured in an OIST press release, “New math bridges holography and twistor theory”. It constitutes a step towards my long-term project of understanding higher-spin holography in de Sitter space.


3.2 Chaos and relative entropy in conformal field theory and holography

Tomonori Ugajin carried out his work on relative entropy in conformal field theories with a gravitational holographic dual. This resulted in a paper in May 2018, which used this quantity to study signatures of chaotic behavior, known to be related to information-scrambling by black holes. Over the following year, Tomonori made a name for himself by finding methods to calculate relative entropy in conformal field theories, and applying it to quantum-gravitational questions.

 

4. Publications

4.1 Journals

  1. Nakagawa, Yuya O., Sárosi, Gábor and Ugajin, Tomonori. Chaos and relative entropy. Journal of high enrergy physics, (2018).
  2. Oda, Satsuki, Okada, Nobuchika, Digesh, Raut and Takahashi, Daisuke. Nonminimal quartic inflation in classically conformal U(1)X extended standard model. Physical Review D, 10.1103/PhysRevD.97.055001 (2018).
  3. Neiman, Yasha. Holographic quantization of linearized higher-spin gravity in the de Sitter causal patch. JHEP, https://doi.org/10.1007/JHEP11(2018)033 (2018)
  4. Stoltenberg, Henry. Properties of the (un)complexity of subsystems, Proc. Natl. Acad. Sci. USA, https://doi.org/10.1103/PhysRevD.98.126012   (2018)


4.2 Books and other one-time publications

Nothing to report
 

4.3 Oral and Poster Presentations

  1. Stoltenberg, Henry. Decoherence in Fluctuations out of Equilibrium, Quantum Information in Cosmology, Copenhagen, Denmark, April 11 (2018).
  2. Ugajin, Tomonori. Relative entropy in CFT, Entanglement in quantum systems, Florence Italy, May 23 (2018).
  3. Ugajin, Tomonori. Scrambling and relative entropy, Strings 2018, Okinawa, Japan, June 25 (2018).
  4. Ugajin, Tomonori. Applications of relative entropy to entanglement, chaos and holography, New frotiers in string theory, Kyoto, Japan, July 6 (2018).
  5. Neiman, Yasha. Holography in the de Sitter causal patch, New Frontiers in String Theory 2018, Kyoto, Japan, July 11 (2018)
  6. Takahashi, Daisuke. R-parity Conserving Minimal SUSY U(1)x Model, 26th International Conference on Supersymmetry and Unification of Fundamental Interactions, Barcelona, Spain, July 24 (2018)
  7. Takahashi, Daisuke. Non-minimal quartic inflation in classically conformal U(1)' extended standard model, 26th International Conference on Supersymmetry and Unification of Fundamental Interactions, Barcelona, Spain, July 24 (2018)
  8. Takahashi, Daisuke. R-parity Conserving Minimal SUSY U(1)x Model, Progress in Particle Physics 2018 (PPP2018), Kyoto, Japan, August 8 (2018)
  9. Ugajin, Tomonori. Applications of relative entropy to entanglement, chaos, and holography, Holography and Geometry of Quantum Entanglement, Seongdong-gu, South Korea, August 13 (2018).
  10. Neiman, Yasha. dS/CFT in the causal patch: Hamiltonian structure for free higher-spin fields, Recent Developments in Gauge Theory and String Theory, Kanagawa, Japan, September 20 (2018)
  11. Ugajin, Tomonori. Relative entropy and Holography, Tokyo, Japan, October 11 (2018)
  12. Ugajin, Tomonori. Strings and Holography (AdS/CFT), Osaka, Japan, November 20 (2018)
  13. Vyacheslav, Lysov. Dual Fluid for the Kerr Black Hole, Kyoto-NTU High Energy Physics Workshop 2018, Okinawa, Japan, November 25 (2018)
  14. Ghosh, Sudip. Coarse grained measures of quantum information, Kyoto-NTU High Energy Physics Workshop 2018, Okinawa, Japan November 27 (2018)

5. Intellectual Property Rights and Other Specific Achievements

Nothing to report

6. Meetings and Events

6.1 Seminars by guest speakers

  • Seminar title: "Aspects of Spinning Witten Diagrams"
  • Date: April 10, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Prof. Heng-Yu Chen (National Taiwan University)
     
  • Seminar title: "Edge modes and entanglement in diffeomorphism-invariant theories"
  • Date: May 15, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Antony Speranza (University of Maryland)
     
  • Seminar title: “Bouncing black holes: A realistic model?"
  • Date: May 29, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Marios Christodoulou (South University of Science and Technology)
     
  • Seminar title: "Black holes in loop quantum gravity: Emergence of non-singular quantum space-time"
  • Date: June 1, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Suddhasattwa Brahma (APCTP, South Korea)
     
  • Seminar title: "New triangulation of the Amplituhedron from sign flip"
  • Date: June 6, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Ryota Kojima (KEK, Japan)
     
  • Seminar title: "Gravity and differential forms"
  • Date: June 19, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Prof. Kirill Krasnov (University of Nottingham)
     
  • Seminar title: "Solitons, Gravity, Gravitating Solitons and Holography"
  • Date: July 31, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Sven Bjarke Gudnason (Keio University)
     
  • Seminar title: "Constraining Quantum Gravity from the Bottom-up"
  • Date: August 14, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Scott Melville (Imperial College London)
     
  • Seminar title: "TOPOLOGICAL DEFECTS, DEFORMED LATTICES AND SPONTANEOUS SYMMETRY BREAKING"
  • Date: August 28, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Vincenzo Vitagliano (Keio University)
     
  • Seminar title: "Vacuum decay rate in the standard model and beyond"
  • Date: October 2, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Yutaro Shoji (Nagoya University)
     
  • Seminar title: "Flow equation, conformal symmetry and AdS geometries"
  • Date: December 4, 2018
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Shuichi Yokoyama (Kyoto University)
     
  • Seminar title: "JTbar deformed CFT2 and string theory"
  • Date: February 20, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Soumangsu Chakraborty (Hebrew University of Jerusalem)
     
  • Seminar title: "Holographic geometries for non-relativistic systems emerging from generalized flow equations"
  • Date: February 21, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Shuichi Yokoyama (Kyoto University)
     
  • Seminar title: "Quantum Black Hole Entropy from 4d Supersymmetric Cardy formula"
  • Date: March 8, 2019
  • Venue: OIST Campus Lab2
  • Speaker: Dr. Masazumi Honda (University of Cambridge)
     

6.2 Workshops by guest speakers and Neiman Unit

  • Date: June 31-July 1, 2018
  • Venue: OIST Campus Lab3
  • Co-organizers: The Institute of All But Cats (IABC)
  • Speakers:
    • Prof. Rajesh Gopakumar (ICTS-TIFR, Bengaluru)
    • Prof. Daniel Grumiller (Vienna University of Technology)
    • Prof. Ergin Sezgin (Texas A&M University)
    • Dr. Dmitry Ponomarev (Texas A&M University)
    • Gerben Venken (KU Leuven)
       
  • Date: November 24-27, 2018
  • Venue: OIST Campus Conference Center
  • Co-organizers: Kyoto University and National Taiwan University
  • Speakers:
    • Song He (Institute of Theoretical Physics, Chinese Academy of Sciences)
    • Eugene Skvortsov (Albert Einstein Institute, Potsdam)
    • Julian Sonner (University of Geneva)
    • Kazuya Yonekura (Kyushu University)

7. Other

Nothing to report.