Old Journal Club: 'Supersymmetry and morse theory'
2026-02-12 17:00 - 18:00 (Europe/Madrid) | Blue Room, Instituto de Física Teórica (IFT) - C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Chuying Wang (IFT) will present ‘Supersymmetry and morse theory’ by Edward Witten J. DIFFERENTIAL GEOMETRY 17 (1982) 661-692
Venue & Time: Blue Room / 17:00
Abstract:
It is shown that the Morse inequalities can be obtained by consideration of a certain supersymmetric quantum mechanics Hamiltonian. Some of the implications of modern ideas in mathematics for supersymmetric theories are discussed.
More info: https://projecteuclid.org/journals/journal-of-differential-geometry/volume-17/issue-4/Supersymmetry-and-Morse-theory/10.4310/jdg/1214437492.pdf

Holo-Club: 'Toward Krylov-based holography in double-scaled SYK'
2026-02-17 11:30 - 13:00 | Gray Room 3, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Speaker: Yichao Fu (GIST)

Title: Toward Krylov-based holography in double-scaled SYK

Venue & Time: Gray Room 3 / 11:30

Abstract:

Building on the duality between Krylov complexity and geodesic length in Jackiw-Teitelboim and sine-dilaton gravity, we develop a precise holographic dictionary for quantities in the Krylov subspace of the double-scaled Sachdev-Ye-Kitaev model (DSSYK). First, we demonstrate that the growth rate of Krylov state complexity corresponds to the wormhole velocity, and show that its expectation value in coherent states serves as a boundary diagnostic of firewall-like structures via bulk reconstruction. We also delineate an alternative bulk description in terms of the proper momentum of an infalling particle at early times, establishing a threefold duality between the Krylov complexity growth rate, wormhole velocity, and proper momentum, with clear regimes of validity. Beyond the first moments, we argue that higher-order Krylov complexities capture connected bulk contributions encoded by replica wormholes, while the logarithmic variant probes the replica saddle structure. Finally, within a third-quantized setting incorporating baby universes, we show that the Krylov entropy equals the von Neumann entropy of the parent-geometry density matrix obtained after tracing out baby universes, thereby quantifying information flow into the baby universe sector. Together, these results elevate Krylov-space observables to sharp probes of bulk dynamics and topology in ensemble-averaged 2D gravity.

Cosmology Journal Club
2026-02-17 14:00 - 15:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Every Tuesday at 2:00 PM in the discussion room on the 5th floor.
Join the IFT cosmology/gravity journal club at benty-fields.com to vote for papers and volunteer to present them.

Quantum Information Journal Club: 'Quantum Algorithms Based on Cooling'
2026-02-18 11:30 - 12:30 | Grey Room 2, Instituto de Física Teórica, Madrid, Madrid, 28037, Spain
Date: Wednesday, February 18
Aula Gris 2 / 11:30
Speaker: Daniel Molpeceres (TU Munich)
Título: Quantum Algorithms Based on Cooling
Abstract: The purpose of this work is to study different methods for nature-inspired algorithmic cooling of physical systems, which rely on energy transfer between the system and a cool bath. These algorithms are suitable for preparation of QMB ground states, and are therefore an alternative to other well-known procedures such as variational or adiabatic algorithm, which have their own limitations. The aim of the paper is to develop this theory, and try to find in what regimes it works best, such that it can be used as an alternative or in collaboration with the previous methods. We will focus on a free-fermion model with hoppings in a 1D lattice and a certain distribution of auxiliary systems per site, try to find regimes in which the system reaches the ground state, and then extrapolate what we learn from this model into a more general noisy setting. The main questions to address are how the performance changes with the noise that may appear in an experimental setting, as well as a comparison with other methods such as adiabatic algorithm or QAOA.

Pheno Journal Club
2026-02-19 12:00 - 13:00 | Gray Room 3, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Every Thursday at 12:00 in Grey Room 3.

Seminar: Primordial black holes from Q-balls
2026-02-19 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Speaker: Shunsuke Neda (ICRR, Univ. of Tokyo)
Venue & Time: Red Room / 15:00
Title: Primordial black holes from Q-balls
Abstract:
We discuss primordial black holes (PBHs) originating from Q-balls, which are non-topological solitons arising in complex scalar field theories with a global U(1) symmetry. Depending on the cosmic expansion history, Q-balls can source PBH formation in both early matter-dominated (eMD) and radiation-dominated (RD) universes, leading to distinct phenomenological consequences.
In the eMD scenario, PBHs produced from Q-balls can account for the observed dark matter abundance, and we summarize the resulting cosmological constraints. In contrast, some scenarios of PBHs formed in a radiation-dominated universe exhibit strong PBH clustering. When motivated as seeds of supermassive black holes, their abundance and spatial distribution are observationally constrained by isocurvature perturbations. For stellar-mass PBHs relevant to LIGO-Virgo-KAGRA, we compute PBH merger rates in the presence of initial PBH clustering using updated methodologies.
This seminar illustrates how PBHs from Q-balls link particle physics models to cosmological, astrophysical, and gravitational-wave observations across multiple mass scales.

Seminar: 'Asymmetric Dark Matter induced by Baryogenesis'
2026-02-23 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Title: ‘Asymmetric Dark Matter induced by Baryogenesis’
Speaker: Miguel Escudero (CERN)
Venue&Time: Red Room / 15:00
Abstract: We live in a Universe where structures are made out of baryons but not of antibaryons. Could the dark matter be made of particles and not antiparticles? This is an old question and many asymmetric dark matter scenarios have been proposed to date. Among them, the models where a dark matter asymmetry is induced from the baryon/lepton asymmetries are particularly motivated. In this seminar, I will highlight the motivations for these types of frameworks but also their challenges. I will then present a new, minimal, and predictive scenario that we developed in [2511.10731]. In this model, a dark matter asymmetry is slowly generated from the Standard Model Higgs doublet asymmetry. The scenario features two dark matter states which can lead to signals in the next generation of dark matter experiments, and we predict a new inert Higgs doublet with mass < 580 GeV which could be produced and observed at the LHC and future colliders.

Seminar by Sei Kato (Institut d'Astrophysique de Paris)
2026-02-26 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
TBA

Seminar by Leandros Perivolaropoulos (Ioannina)
2026-03-02 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Robert Brandenberger (McGill)
2026-03-05 15:00 - 17:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Lorenz Eberhardt (U. Amsterdam)
2026-03-09 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Jeroen Monnee
2026-03-12 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

IFT Seminar Mikael Chala (Granada)
2026-03-16 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Sung Mook Lee
2026-03-19 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Roberto Emparan (Universidad de Barcelona)
2026-03-23 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Jose Beltran (Salamanca)
2026-04-13 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Iñaki Garcia Etxebarria
2026-04-16 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Isaac Tutusaus (ICE, Barcelona)
2026-04-20 15:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

IFT seminar: Mikel Sanchez-Garitaonandia
2026-04-27 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

IFT seminar: Alberto Roper Pol (Geneva)
2026-05-04 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Holo-Club by Martin Sasieta (U. Berkeley)
2026-05-12 11:30 - 13:00 | Gray Room 3, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain

Seminar by Felix Yu (Mainz U.)
2026-05-21 15:00 - 16:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
