FY2019 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 and on field theory in de Sitter space. LinQing Chen and Vyacheslav Lysov worked on the relationship between boundary degrees of freedom and gauge symmetry. Tomonori Ugajin worked on relative entropy in conformal field theories and holography. Sudip Ghosh worked on the thermal behavior of Chern-Simons-matter theories, as well as on a holographic picture for scattering amplitudes in flat spacetime. Dorin Weissman worked on string theory in non-critical dimensions.

1. Staff

  • Dr. Mirian Tsulaia, Staff Scientist
  • Dr. Sudip Ghosh, Postdoctoral Scholar
  • Dr. LinQing Chen, Postdoctoral Scholar
  • Dr. Vyacheslav Lysov, Postdoctoral Scholar
  • Dr. Tomonori Ugajin, Postdoctoral Scholar
  • Dr. Dorin Weissman, Postdoctoral Scholar
     

2. Collaborations

Quantum chiral higher-spin gravity

  • Description: This resulted in a joint preprint in February 2020, published in May 2020.
  • Type of collaboration: Joint research
  • Researchers:
    • Dr. Mirian Tsulaia, OIST
    • Dr. Evgeny Skvortsov, Albert Einstein Institute in Potsdam
    • Dr. Tung Tran, Albert Einstein Institute in Potsdam

Thermal correlators and dualities in Chern-Simons-matter theories

  • Description: This resulted in a joint preprint in December 2019.
  • Type of collaboration: Joint research
  • Researchers:
    • Dr. Sudip Ghosh, OIST
    • Dr. Subhajit Mazumdar, Hebrew University in Jerusalem

Scattering amplitudes as celestial correlators

  • Description: This resulted in a joint publication in March 2020, and a second joint preprint in February 2020, published in April 2020.
  • Type of collaboration: Joint research
  • Researchers:
    • Dr. Sudip Ghosh, OIST
    • Dr. Shamik Banerjee, IPMU in Tokyo and Indian Institute of Science in Bangalore.
    • Pranjal Pandee, Institute of Physics in Bhubaneswar and HNBI in Mumbai.
    • Dr. Arnab Priya Saha, Harish-Chandra Research Institute.
    • Ricardo Gonzo, Hamilton Mathematical Institute in Dublin.

Rotating strings in non-critical dimensions

  • Description: This work is now being prepared for publication.
  • Type of collaboration: Joint research
  • Researchers:
    • Dr. Dorin Weissman, OIST
    • Dr. Jacob Sonnenschein, Tel Aviv University
       

3. Activities and Findings

3.1 Thermal behavior and dualities in Chern-Simons-matter theories

In recent years, significant progress has been made on quantum field theories in 3 dimensions, mainly Chern-Simons gauge theories coupled to matter. These theories turn out to be connected by a web of dualities, even in the absence of supersymmetry. They are of interest both directly as describing condensed matter systems, and as the holographic duals of higher-spin gravity. In a December 2019 preprint, Sudip Ghosh with collaborators calculated thermal correlation functions in such theories. This served both as a new test of the dualities, and as a probe into the behavior of black holes (or their analogues) in higher-spin gravity.

3.2 Quantum chiral higher-spin gravity

Mirian Tsulaia (staff scientist) with collaborators has been developing a chiral interacting theory of higher-spin gravity, with or without a cosmological constant. This is the most explicit higher-spin theory to date, and the only one in which the interactions can be computed directly at the quantum level. Aside from its intrinsic interest, it constitutes a stepping stone towards understanding full higher-spin gravity, just as the chiral versions of Yang-Mills theory and General Relativity do for lower spins, In a February 2020 preprint (published in May), they applied the chiral higher-spin theory in anti-de Sitter space to provide new understanding of the bozonisation dualities of the Chern-Simons-matter theories on its boundary (the subject of Sudip Ghosh’s work above), along with previously unknown results.

3.3 Scattering amplitudes in observable patches in de Sitter space

Yasha Neiman with students made headway into on a previously neglected elementary question of mathematical physics: that of the scattering amplitudes between an observer’s initial and final horizons in de Sitter space. In an August 2019 publication with Adrian David (Ph.D. student) and Nico Fischer (intern), we developed a spinor-helicity language for de Sitter horizons, and used it to express the free scattering amplitudes for massless fields of all spins. In an ongoing collaboration with Emil Albrychiewicz (intern), we are now including leading-order interactions, i.e. those of Yang-Mills theory (for spin 1) and General Relativity (for spin 2). This should provide a framework for thinking about the scattering amplitudes of higher-spin gravity, or of its chiral version that is under development by Mirian Tsulaia.

3.4 Scattering amplitudes in flat spacetime as celestial correlators

There is an ongoing effort to understand the scattering amplitudes of gravity and field theory in asymptotically flat spacetime in terms of something resembling a conformal field theory (CFT) on its boundary, i.e. at lightlike infinity. The relevant symmetry in this case should be the BMS symmetry of lightlike infinity, instead of the Virasoro symmetry of ordinary 2-dimensional conformal field theory. In a March 2020 publication and a February 2020 preprint, Sudip Ghosh and collaborators have further developed the dictionary between flat-spacetime amplitudes and CFT-like quantities, and have studied how the amplitudes may be organized into representations of the BMS group.
 

4. Publications

4.1 Journals

  1. David, Adrian., Fischer, Nico., and Neiman, Yasha. Spinor-helicity variables for cosmological horizons in de Sitter space. Physical Review D, https://doi.org/10.1103/PhysRevD.100.045005 (2019)
  2. Banerjee, Shamik., Ghosh, Sudip., Pandey, Pranjal., and Saha, Arnab Priya.  Modified celestial amplitude in Einstein gravity. JHEP, 10.1007/JHEP03(2020)125 (2020).

4.2 Books and other one-time publications

      Nothing to report

4.3 Oral and Poster Presentations

  1. Ugajin, Tomonori. Panel Discussion Recent developments in AdS/CFT, Workshop on recent developments in AdS/CFT, Okinawa, Japan, April 2 (2019)
  2. Ugajin, Tomonori. Modular Hamiltonians of excited states, OPE blocks and emergent bulk fields, Theoretical Particle Physics Group, Department of Physics, Graduate School of Science, Hokkaido University, Hokkaido, Japan, April 19 (2019).
  3. Ghosh, Sudip. Thermal Correlators in Chern Simons Matter Theories and Bosonisation Dualities, International Centre for Theoretical Sciences, Begaluru, India, June 6 (2019).
  4. Neiman, Yasha. Spinor-helicity variables and codimension-2 holography in de Sitter space, Hebrew Univ. of Jerusalem, Jerusalem, Israel, June 27 (2019)
  5. Ghosh, Sudip. Thermal Correlators and Bosonisation Dualities in Large N Chern Simons Matter Theories, Strings 2019, Brussels, Belgium, July 9 (2019)
  6. Lysov, Vyacheslav. Journey to the microscopic derivation of the Bekenstein-Hawking formula, The OIST Workshop "Quantum and Gravity in Okinawa" 2019, Okinawa, Japan, July 24 (2019)
  7. Ghosh, Sudip. Thermal Correlators and Bosonization Duality in Large N Chern Simons Matter Theories, Korea Institute for Advanced Study, Daejeon, South Korea, September 2 (2019)
  8. Neiman, Yasha. Higher-spin gravity in the de Sitter causal patch, Perimeter Institute for Theoretical Physics, Waterloo, Canada, September 4 (2019)
  9. Neiman, Yasha. Higher-spin theory in the de Sitter causal patch, Higher Spin Gravity -Chaotic, Conformal and Algebraic Aspects, Pohang, South Korea, October 1 (2019)
  10. Ghosh, Sudip. Thermal Correlators and Bosonisation Dualities in Large N Chern Simons Matter Theories, YITP, Kyoto University, Kyoto, Japan, November 29 (2019)
  11. O’Connell, David. Lorentzian Structures on Branching Spacetimes, The London School of Economics, London, UK, January 30 (2020)
     

5. Intellectual Property Rights and Other Specific Achievements

Nothing to report
 

6. Meetings and Events

6.1 Seminars by guest speakers

  • Seminar title: " Higher Spin Supermultiplets in Various Dimensions "
  • Date: April 9, 2019
  • Venue: OIST Campus Lab2
  • Speaker: Dr. Mirian Tsulaia (Ilia State University)
     
  • Seminar title: " The GEODE mass function and its astrophysical implications "
  • Date: April 10, 2019
  • Venue: OIST Campus Lab2
  • Speaker: Kevin Croker (University of Hawaii at Manoa)
     
  • Seminar title: “Circuit Complexity in Conformal Field Theories?"
  • Date: May 16, 2019
  • Venue: OIST Campus Lab1
  • Speaker: Dr. Pawel Caputa (Kyoto University)
     
  • Seminar title: " Decoherence and Einselection in Equilibrium in an adapted Caldeira Leggett model "
  • Date: May 27, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Prof. Andreas Albrecht (QMAP/UC Davis)
     
  • Seminar title: " Quantum entanglement between bubble universes "
  • Date: June 29, 2019
  • Venue: OIST Campus Lab1
  • Speaker: Sugumi Kanno (Osaka University)
     
  • Seminar title: " Entanglement Branes, Modular Flow, and Extended TQFT "
  • Date: July 4, 2019
  • Venue: OIST Campus Lab1
  • Speaker: Dr. Gabriel Wong (Fudan Unviersity)
     
  • Seminar title: " Multi-messenger Extended Emission from the compact remnant in GW170817"
  • Date: July 9, 2019
  • Venue: OIST Campus Lab1
  • Speaker: Prof. Maurice van Putten (Sejong University)
     
  • Seminar title: " Making string theory great again "
  • Date: December 2, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Prof. Eoin Ó Colgáin (APCTP)
     
  • Seminar title: " Out of time ordered effective dynamics of a quartic oscillator "
  • Date: December 10, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Bidisha Chakrabarty (ICTS-TIFR)
     
  • Seminar title: " Tensionless Strings from worldsheet perspective "
  • Date: December 16, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Aritra Banerjee (APCTP)
     
  • Seminar title: " Classical soft theorem in four dimension "
  • Date: January 23, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Dr. Arnab Priya Saha (Harish-Chandra Research Institute)
     
  • Seminar title: " Surface operators in N=2 SQCD and Seiberg Duality "
  • Date: January 24, 2019
  • Venue: OIST Campus Lab3
  • Speaker: Sourav Ballav (The Institute of Mathematical Sciences, Chennai)
      

6.2 Workshop by guest speakers and Neiman Unit

  • Workshop on recent developments in AdS/CFT
  • Date: April 2-3, 2019
  • Venue: OIST Campus Conference Center, Meeting Room 1
  • Organizers: Tomonori Ugajin (OIST Neiman Unit) 
                        Norihiro Iizuka (Osaka University)
  • Speakers:
    • Pawel Caputa (YITP, Kyoto University)
    • Frank Ferrari (Université Libre de Bruxelles)
    • Koji Hashimoto (Osaka University)
    • Norihiro Iizuka (Osaka University)
    • Akihiro Ishibashi (Kindai University)
    • Kengo Maeda (Shibaura Institute of Technology)
    • Tatsuma Nishioka （Tokyo University)
    • Masaki Shigemori (Nagoya University)
    • Junggi Yoon (Korea Institute for Advanced Study)
    • Kentaro Yoshida (Kyoto University) 
       

7. Other

Nothing to report.