This workshop is about the three different signs of the cosmological constant, the three resulting maximally symmetric spacetimes and their correspondence with conformal field theory. We are bringing together experts on these three aspects of holography to discuss and exchange ideas leading towards its broader understanding. The workshop targets a broad audience of senior researchers as well as postdocs and PhD students. We have scheduled four pedagogical review talks, six technical talks, poster session and discussion sessions.


16th May
17th May
18th May
19th May
8:30 - 9:25 Registration
9:25 - 9:30 Opening
09:30-10:45 Monica Guica Diego Hofman Ana-Maria Raclariu Hong Liu
10:45-11:15 Break
11:15-12:15 Alejandro Cabo Bizet Damián Galante Adrien Fiorucci David Kubizňák
12:15-14:15 Lunch End of workshop
14:15-15:00 Sameer Murthy Discussion Discussion
15:00-16:00 Dan Kapec Andreas Blommaert Paolo Benincasa
16:00-16:30 Break
16:30-18:00 Dionysios Anninos GONG SHOW Discussion
Beer Time @ Letna


Monica Guica IPhT Saclay
Irrelevant deformations and holography Abstract
Diego Hofman University of Amsterdam
Review of dS holography Review of dS holography
David Kubizňák Charles University
Closing remarks Abstract
Hong Liu MIT
Emergence of space and time in holography I will first review the essential aspects of the AdS/CFT duality, with an eye toward possible generalization to flat or de Sitter spacetime. I will then discuss recent progress in understanding emergence of space, time, and causal structure in AdS from the boundary theory.
Ana-Maria Raclariu University of Amsterdam
Progress in Flat Space Holography Celestial holography proposes a duality between the gravitational S-matrix and correlators in a conformal field theory living on the celestial sphere. I will review some of the key features of this proposal, highlighting the importance of symmetries and discuss a few recent applications, including new insights into the gravitational phase space, scattering in non-perturbative backgrounds, connections to twistor theory and the flat space limit of AdS/CFT.


Paolo Benincasa Max Planck Institute, Munich
A Combinatorial Perspective on dS holography The formulation of a holographic description of the physics in asymptotically de Sitter (dS) space-times would provide a microscopic theory for it. The isometries of dS have suggested to look for such a formulation in terms of a conformal field theory. However, there are several indications for which the field theory languange we are occostumed to might not be the most adecuate one, especially if we aim to have a holographic formulation which fully captures the quantum effects of dynamical gravity. In this talk, I'll present recent progress in providing a first-principle mathematical formulation for observables defined at the future boundary of dS in terms of certain polytopes. The underlying idea is that the usual principles we know or aspect to hold emerge from the mathematical principles on which they are based.
Andreas Blommaert SISSA
Path integrals for DSSYK - towards deriving dS holography I will discuss a formulation of double scaled SYK amplitudes in terms of representation theory of a quantum group, and derive from this two path integral formulations of DSSYK. One of them, the q-Schwarzian, should be viewed as the generalization of the Schwarzian description of low energy SYK. I will then present a gravitational path integral which is holographically dual to this q-Schwarzian, which I show by going through its first order gauge-theory formulation. This dilaton gravity model dual to DSSYK has regions of both AdS and dS, as anticipated by Susskind and friends. As such this system presents an opportunity to derive dS holography top-down in a UV complete model. Based on work with Thomas Mertens and Shunyu Yao which will appear soon.
Adrien Fiorucci TU Vienna
Sourced Carrollian CFTs & Flat Space Holography Gravity in four-dimensional asymptotically flat spacetime constitutes the archetypal example of a gravitational system with leaky boundary conditions. In this talk, I will argue that the holographic description of such a system re- quires the coupling of the dual theory living at null infinity to some external sources encoding the radiation reaching the conformal boundary and respon- sible for the non-conservation of the charges. To formalize this coupling, I will introduce a generalized concept of variational symmetries and derive related Ward identities perturbed by the presence of sources. When applied to a con- formal Carrollian field theory living at null infinity, these identities reproduce the BMS flux-balance laws. The source operators are identified with the boundary value of radiative fields in the bulk, in such a way that correlators of source op- erators holographically encode massless scattering amplitudes. Moreover, the constraints imposed on these correlators by the sourced Ward identities are actually equivalent to soft theorems. Finally, I will derive the general form of low-point correlation functions for conformal Carrollian field theories using sym- metry arguments and exhibit a new branch of distributional solutions, which is the relevant one for holographic purposes.
Damián Galante King's College London
Holography inside the dS static patch I will describe recent progress in trying to formulate a holographic theory inside the static patch of dS_2 by appending it to an AdS boundary. In this way, I can cover 2/3 of the workshop. I will describe some salient features of these spacetimes and propose a microscopic dual for them in terms of particular deformations of the SYK model.
Daniel Kapec Harvard
The Geometry of the Space of Celestial CFTs Celestial CFT” is a formalism which attempts to recast quantum gravity in (d+2)-dimensional asymptotically flat spacetimes in terms of a d-dimensional Euclidean CFT residing at the conformal boundary. I will discuss certain universal aspects of this correspondence. As in anti-de Sitter space, bulk gravitons produce a boundary stress tensor, and bulk gluons furnish boundary conserved currents. I will also show that continuous spaces of vacua in the bulk map directly onto the conformal manifold of the boundary CFT. This correspondence provides a new perspective on the role of the BMS group in flat space holography, and offers a new interpretation of the antisymmetric double-soft gluon theorem in terms of the curvature of an infinite-dimensional vacuum manifold.
Alejandro Cabo Bizet University of Salento & INFN Lecce
Statistical physics at large charges: lessons from AdS/CFT Using tools from both sides of AdS/CFT, it has recently been shown that large BPS states on the CFT side of the duality can be understood as microscopic components of the large black holes in AdS5xS5 and AdS4xS7 carrying the same global charges. In this talk, I will review some of the developments that lead to these results, with an emphasis on universal lessons that may help in understanding or uncovering new features of AdS/CFT or other physical systems of interest.


Sameer Murthy King's College London
Recent developments in exact AdS/CFT: what do we learn? in the last few years, we have learned how to incorporate perturbative 1/N corrections and non-perturbative exp(-N) effects in the context of various supersymmetric indices in AdS/CFT. I will briefly recapitulate this progress and attempt to elicit a discussion about its importance and where we go from here.
Dionysios Anninos King's College London
All Lambda discussion Abstract


Dionysios AnninosKing’s College London
Cynthia AriasCharles University
Jose BarrientosInstitute of Mathematics, CAS
Paolo BenincasaMax-Planck-Institut für Physik
Andreas BlommaertSISSA
Alejandro Cabo BizetUniversity of Salento & INFN Lecce
Adolfo CisternaInstitute of Mathematics of the Czech Academy of Sciences
Felipe DiazUnivesidad Andres Bello
Adrien FiorucciTechnische Universität Wien
Damian GalanteKing's College London
Dražen GlavanCEICO, FZU
Monica GuicaIPhT, CEA/Saclay
Diego HofmanUniversity of Amstertdam
Sk Jahanur HoqueInstitute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University
Daniel KapecHarvard University
Jani KastikainenAPC, Université Paris Cité
David KubiznakCharles University
Hong LiuMIT
Anna MorozovaFZU
Ruggero NorisCEICO, Institute of Physics of the Czech Academy of Sciences
Valentin NOURRYAPC, Université Paris Cité
Simon PekarUniversity of Mons
Tomáš ProcházkaInstitute of Physics of the Czech Academy of Sciences
Ana RaclariuUniversity of Amsterdam
Joris RaeymaekersCeico, Prague
Paolo RossiCEICO - Charles University
Canberk SanliCEICO
Ashish ShuklaEcole Polytechnique
Constantinos SkordisCEiCO - FZU, Institute of Physics of the Czech Academy of Sciences
Georg StettingerPrague Academy of Science
Gizem ŞengörBoğaziçi University
Tayebeh TahamtanITP, Charles University
Georg TrenklerCEICO
Jaroslav TrnkaUC Davis & Charles University
Samuel ValachTrinity College Dublin
Petr VaskoCharles University
David VeghQueen Mary University of London
Matthieu VilatteEcole Polytechnique de Paris
Gideon VosCEICO


Mohamed AbdulazeemSohag University
Mir AfrasiarIIT Kanpur
Evangelos AfxonidisUniversity of Oviedo
Shabeeb Alalawikfupm
Gabriel Arenas-HenriquezDurham University
Sourish Banerjee BanerjeeBITS Pilani K K Birla Goa Campus
Debarshi BasuIndian Institute of Technology Kanpur
Klaus BeringMasaryk U
Somdatta Bhattacharyaunaffiliated
Swastik BhattacharyaBITS-Pilani Hyderabad Campus
James BonifacioUniversity of Mississippi
Manizheh BotshekananfardBoğaziçi University
Bruno BucciottiScuola Normale Superiore, Pisa
Ayan ChatterjeeCentral University of Himachal Pradesh
Mario CretìUnisalento
Arnaud DelfanteUniversity of Mons
Ceren A DeralBogazici University
Sarthak DuaryInternational Centre for Theoretical Sciences, Bangalore
Wanxiang FanUniversity of Southampton
Silvia GeorgescuIPhT Saclay and CPHT, Ecole polytechnique
Jewel GhoshIndependent University, Bangladesh (IUB)
Nishant GuptaInstitute of Mathematical Sciences, Chennai
Jan HladíkInstitute of Physics in Opava, Silesian University in Opava
Krishna JalanIMSc, Chennai, India
Alexandros KanargiasUniversity of Mainz, Germany
Maria KnyshVrije Universiteit Brussel
Emine Şeyma Kutlukİstanbul Technical University
Pan LiInstitute of High Energy Physics of Chinese Academy of Sciences
stefano lionettiUnisalento
Daniel LogaresOviedo University
Kevin LooTsinghua University
Dario MelleUnisalento
Delaram MirfendereskiUniversity of Rio Grande Valley
Sukrut MondkarIndian Institute of Technology Madras
Sameer MurthyKing's College London
Pratik NandyYITP, Kyoto
Mrityunjay NathIIT Indore
Vijay NenmeliUniversity of Cambridge
Sergei OvchinnikovUniversity of Edinburgh
Kuntal PalIndian Institute of Technology Kanpur
Kunal PalIndian Institute of Technology Kanpur
Himanshu PariharNational Center for Theoretical Sciences, National Tsing Hua University, Taiwan
Praneet PathakIISER Mohali, India
Sivasish PaulRKMVERI, Belur
Mak PavičevićSISSA
Andrea PuhmCNRS and CPHT, Ecole Polytechnique
Vinayak RajIndian Institute of Technology Kanpur
PABITRA RAYInternational Centre for Theoretical Sciences
Lorenzo RossiQueen Mary University of London
Romain RuzziconiTU Vienna
Debajyoti SarkarIIT Indore
Ignacy SawickiCEICO, Prague
Sergio Ernesto Aguilar Gutierrez Sergio Ernesto Aguilar GutierrezKU Leuven
Sanjit ShashiUniversity of Texas, Austin
Rajeev SinghStony Brook University
Akash SinghIISER Mohali (India)
Ryo SuzukiShing-Tung Yau Center of Southeast University
Abinash SwainPune University, India
poula tadrosAalto university
Riccardo TommasiUniversità del Salento
Martin VinczePublic
Rikard von UngeMasaryk University
Gopal YadavIndian Institute of Technology Roorkee
Chen YangScuola Normale Superiore
Utku ZorbaBoğaziçi University


Registration is now closed.


    The workshop will take place at the Solid21 building of the Institute of Physics, Czech Academy of Sciences. A map showing how to walk there from Ladvi metro station is embedded below.

    NOTE: Lunch is not provided -- participants are expected to arrange their own lunch.

    There are several restaurants in the nearby Ladvi area (close to the metro station) including:

    • Jidenla Slovanka Canteen, typically used by researchers and staff of the nearby institutes. Has salad bar and at least one vegetarian dish. Address: U Slovanky 5a, Praha 8
    • Lapak Czech dishes. Address: Kyselova 1657, Praha 8
    • Cobolis Microbrewery, with good beer and czech dishes. Address: Burešova 1661/2 Praha 8
    • Pizzeria Mexicana Giovanni Italian/Mexican style pizza and other dishes. Address: Střelničná 1826/35 Praha 8
    • Vietnamese bistro Nhat Hai Nice Vietnamese bistro (Limited capacity). Address: Kyselova 1191/11, Praha 8

    • For those who want to take a longer break, here's some places in the Letna area (go to station Vltavska on line C). Put aside around 30 mins of transit time each way.

    • Pokehaus A pretty good Hawaiian place. Address: M. Horákové 386/63,Praha 7
    • Hillbilly A burger place. Address: Pplk Sochora 21. Praha 7
    • Forky's A vegan place. Address: M. Horákové 16, Praha 7
    • Vegtral Another vegan place. Address: Čechova 12, Praha 7
    • Kovadlina u Lazni Nice local bar with (limited) Czech style pub food. Address: Kostelní 8, Praha 7
    • San Carlo Pizzeria. Address: Milady Horákové 1280/9, Praha 7
    • Bar Cobra Cocktail bar with a surprisingly extensive, high-quality food menu. Address: Milady Horákové 8, Praha 7

    Informal gathering: Tuesday evening

    Letna lookout beer garden at Letna park (closest station is Vltavska).