Journal club

We plan to organize a seminar on string field theory (SFT) and related topics (worldsheet theory, string amplitudes, compactifications, homotopy algebras…) on Friday every 2 weeks. Talks are 1.5 hours long: the recommended format is a general introduction of 30 min for students and non-specialists (especially, before technical talks), 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. Seminars are preceded by an informal discussion on and Zulip will be used for continuing discussions after the talk. 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):

  • 14:30 – 15:00 (CEST) [8:30 (EST), 18:00 (IST), 22:30 (JST)] : informal discussion on
  • 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 links for Zoom, and Zulip. 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 Videos of the recorded talks will be posted in the String field theory Youtube channel. You can contact us for suggesting speakers.


  • Friday 29 October 2021: Barton Zwiebach (CTP, MIT)
    Title: Nonlocal field theory, rolling tachyons, and initial value problem (recording, slides)

    Abstract: We consider a nonlocal scalar field theory inspired by the tachyon action in open string field theory and p-adic string models. We study in detail field redefinitions that re-cast the theory in a form with a clear initial value problem. We discuss rolling tachyons and issues of causality.

  • Friday 12 November 2021 : Carlo Maccaferri (Università di Torino)
    Title: D-branes potentials and closed string deformations in open string field theory (recording, slides)

    Abstract: I discuss recent results on the effective potential of various D-branes systems in both bosonic string theory and Type II superstring. I focus on open string field theories based on Witten’s star product for which we know how to construct exact classical solutions and where the coupling with deforming closed strings can be obtained via a simple open/closed gauge invariant vertex. The obtained effective algebraic couplings can be understood as zero-momentum amplitudes where all possible infrared divergences arising from open string degeneration are systematically tamed by the open string propagator. I also discuss how one can possibly handle similar divergences from closed string degeneration, when a closed string deformation is added to the pure open string theory.

  • Friday 3 December 2021 : Nathan Berkovits (ICTP-SAIFR, IFT-UNESP)
    Title: Applications of the $N=1, d=4$ spacetime-supersymmetric version of open superstring field theory (recording)

    Abstract: I will first review the version of open superstring field theory based on the hybrid formalism which has manifest $N=1, d=4$ spacetime supersymmetry. I will then discuss two recent applications including the equations of motion for higher-spin massive fields in an electromagnetic background and the computation of stringy corrections to the self-dual $d=4$ instanton solution.

  • Thursday 27 January 2022 : Ashoke Sen (ICTS)
    Title: TBA

  • Thursday 10 February 2022 : Yuji Okawa (Tokyo U.)
    Title: TBA