Journal club

We are organizing a seminar on string field theory (SFT) and related topics (worldsheet theory, string amplitudes, compactifications, homotopy algebras…) on Thursday every 2 weeks. Talks are typically 1.5 hours long, but they may be longer for topics when necessary.

Our goal is to offer reviews, mini-lectures and communications of recent results. In the latter case, the recommended format is a general introduction of 30 min for students and non-specialists, followed by 1 hour of talk + discussions intertwined. However, speakers are free to organize their time differently. Speakers can present one of their papers, work in progress or even other papers they want to discuss. We hope that this regular journal club will help foster discussions within the SFT community and related fields and seed new collaborations and applications.

Structure (reference timezone is CEST, see this website for conversion):

  • 15:00 – 16:30 (CEST) [9:00 (EST), 19:30 (IST), 23:00 (JST)] : talk

Please register on the mailing list for announcements and obtaining the Zoom link. If you don’t see emails, please check your spam folder and, if necessary, mark the email as non-spam.


  • Subhroneel Chakrabarti (CEICO, Prague)
  • Harold Erbin (MIT & IAIFI, Boston; CEA-LIST, Paris)
  • Renann Lipinski Jusinskas (CEICO, Prague)

Talks will be announced on this page and through the mailing list. You can also consult the calendar or events pages or subscribe to the SFT Google Calendar (ics version). Talks are also listed on Everyone is invited to discuss on Zulip.

Videos of the recorded talks will be posted in the String field theory Youtube channel.

Past seminars:

You can contact us for suggesting speakers.


  • Thursday 12 January 2023 : Kevin Costello (Perimeter Institute) (cancelled, to be rescheduled)
    Title: Twisted supergravity and string field theory

    Abstract: Twisted supergravity is ordinary supergravity in a background where the superghost has a vev. I will review what is known about twisted supergravity. I will also discuss some joint work with Si Li, where we give a string field theory inspired argument for how to quantize twisted IIB supergravity.
  • Thursday 26 January 2023 : Aron Wall (Cambridge U.)
    Title: The Off-shell String Effective Action

    Abstract: Taking string theory off shell requires breaking Weyl invariance on the worldsheet, i.e. the worldsheet theory is now a QFT instead of a CFT. I will explain Tseytlin’s approach to taking the worldsheet theory off-shell in a consistent manner, with a particular emphasis on the subtleties involved in calculating the sphere amplitude. This approach allows for the derivation of a classical string action which gives rise to the correct equations of motion and S-matrix, to all orders in perturbation theory. I will also attempt to explain how the resulting off-shell effective tree amplitudes are related to string field theory. Based on arXiv:2211.08607
  • Thursday 09 February 2023 : Amr Ahmadain (Cambridge U.)
  • Thursday 23 February 2023 : Hong Liu (MIT)
  • Thursday 09 March 2023 : Nobuyuki Ishibashi (Tsukuba U.)
  • Thursday 23 March 2023 : Piotr Tourkine (Université de Savoie)
  • Thursday 06 April 2023 : TBA
  • Thursday 20 April 2023 : TBA
  • Thursday 04 May 2023 : Manki Kim (MIT)
  • Thursday 18 May 2023 : TBA