Skip to main content
Home
Department Of Physics text logo
  • Research
    • Our research
    • Our research groups
    • Our research in action
    • Research funding support
    • Summer internships for undergraduates
  • Study
    • Undergraduates
    • Postgraduates
  • Engage
    • For alumni
    • For business
    • For schools
    • For the public
Menu
A blackboard in my office

John Wheater

Professor of Physics, Head of Particle Theory Group

Research theme

  • Fundamental particles and interactions
  • Fields, strings, and quantum dynamics

Sub department

  • Rudolf Peierls Centre for Theoretical Physics

Research groups

  • Particle theory
John.Wheater@physics.ox.ac.uk
Telephone: 01865 (2)73961
Rudolf Peierls Centre for Theoretical Physics, room 60.06
  • About
  • Research
  • Teaching
  • Publications

F -extremization determines certain large- N CFTs

Journal of High Energy Physics Springer 2025:4 (2025) 85

Authors:

Ludo Fraser-Taliente, John Wheater

Abstract:

We show that the conformal data of a range of large-N CFTs, the melonic CFTs, are specified by constrained extremization of the universal part of the sphere free energy F = − log ZSd, called F~. This family includes the generalized SYK models, the vector models (O(N), Gross-Neveu, etc.), and the tensor field theories. The known F and a-maximization procedures in SCFTs are therefore extended to these non-supersymmetric CFTs in continuous d. We establish our result using the two-particle irreducible (2PI) effective action, and, equivalently, by Feynman diagram resummation. The universal part of F~ interpolates in continuous dimension between the known C-functions, so we can interpret this result as an extremization of the number of IR degrees of freedom, in the spirit of the generalized c, F, a-theorems. The outcome is a complete classification of the melonic CFTs: they are the conformal mean field theories which extremize the universal part of the sphere free energy, subject to an IR marginality condition on the interaction Lagrangian.
More details from the publisher
Details from ORA

Melonic limits of the quartic Yukawa model and general features of melonic CFTs

Journal of High Energy Physics Springer 2025:1 (2025) 187

Authors:

Ludo Fraser-Taliente, John Wheater

Abstract:

We study a set of large-N tensor field theories with a rich structure of fixed points, encompassing both the melonic and prismatic CFTs observed previously in the conformal limits of other tensor theories and in the generalised Sachdev-Ye-Kitaev (SYK) model. The tensor fields interact via an O(N) 3 -invariant generalisation of the quartic Yukawa model, ϕ 2ψψ¯ +ϕ 6 . To understand the structure of IR/UV fixed points, we perform a partial four-loop perturbative analysis in D = 3 − ϵ. We identify the flows between the melonic and prismatic fixed points in the bosonic and fermionic sectors, finding an apparent line of fixed points in both. We reproduce these fixed points non-perturbatively using the Schwinger-Dyson equations, and in addition identify the supersymmetric fixed points in general dimension. Selecting a particular fermionic fixed point, we study its conformal spectrum non-perturbatively, comparing it to the sextic prismatic model. In particular, we establish the dimensional windows in which this theory remains stable. We comment on the structure of large-N melonic CFTs across various dimensions, noting a number of features which we expect to be common to any such theory.

More details from the publisher
Details from ORA

$F$-extremization determines certain large-$N$ CFTs

(2024)

Authors:

Ludo Fraser-Taliente, John Wheater
More details from the publisher

Melonic limits of the quartic Yukawa model and general features of melonic CFTs

(2024)

Authors:

Ludo Fraser-Taliente, John Wheater
More details from the publisher

Globalisation: The physics landscape today

Journal of Physics Conference Series IOP Publishing 2877:1 (2024) 012019
More details from the publisher

Pagination

  • Current page 1
  • Page 2
  • Page 3
  • Page 4
  • Page 5
  • Page 6
  • Page 7
  • Page 8
  • Page 9
  • …
  • Next page Next
  • Last page Last

Footer Menu

  • Contact us
  • Giving to the Dept of Physics
  • Work with us
  • Media

User account menu

  • Log in

Follow us

FIND US

Clarendon Laboratory,

Parks Road,

Oxford,

OX1 3PU

CONTACT US

Tel: +44(0)1865272200

University of Oxfrod logo Department Of Physics text logo
IOP Juno Champion logo Athena Swan Silver Award logo

© University of Oxford - Department of Physics

Cookies | Privacy policy | Accessibility statement

Built by: Versantus

  • Home
  • Research
  • Study
  • Engage
  • Our people
  • News & Comment
  • Events
  • Our facilities & services
  • About us
  • Current students
  • Staff intranet