SPS Journal Club: 'Tensionless String Limits in AdS5/CFT4 and the Sharpened Distance Conjecture'
2026-04-23 12:00 - 13:00 (Europe/Madrid) | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Strings, Pheno and the Swampland (SPS) Journal Club. Every Thursday at 12:00 in the Red Room.

Title: Tensionless String Limits in AdS5/CFT4 and the Sharpened Distance Conjecture

Speaker: Gabriel Fenati (IFT)

Venue&Time: Red Room / 12:00

Abstract: Based on work in progress with M. Montero and I. Valenzuela. We extend the results of [2410.07309] by showing that all 4d Lagrangian SCFTs satisfy the bound of the Sharpened Distance Conjecture in the large N limit. We also provide an example of a quiver SCFT, dual to a stringy AdS background, where the bound is violated by taking a different kind of semi-classical limit, in which the number of gauge factors is taken to be large at fixed N.

Pheno Journal Club: 'Infinite Heat Order in 3+1 Dimensions'
2026-04-23 12:00 - 13:00 | Grey Room 2, Instituto de Física Teórica, Madrid, Madrid, 28037, Spain
Samuel Rosende (IFT) will present “Infinite Heat Order in 3+1 Dimensions”

Venue&Time: Gray Room 2 / 12:00

Abstract:

We investigate whether spontaneous symmetry breaking can persist up to arbitrarily high temperature in ultraviolet-complete quantum field theories in four spacetime dimensions. We focus on completely asymptotically free models with gauge group SU(Nc1)×SU(Nc2) and two complex scalar fields, each transforming in the fundamental representation of one gauge factor and singlet under the other. The scalar potential contains quartic self-interactions together with a negative portal coupling between the two sectors. In the Veneziano limit, this class of theories was previously shown to admit fixed-flow trajectories for which one scalar acquires a negative thermal mass at asymptotically large temperature, leading to symmetry non-restoration. Here we extend that analysis to finite numbers of colours and flavours. We derive the finite-N fixed-flow equations, compute the leading 1/N corrections to the large-N solutions, and solve the full finite-N system numerically. We find explicit finite-N benchmark theories for which the scalar potential remains bounded from below, the gauge sector is asymptotically free, and one scalar thermal mass stays negative at arbitrarily high temperature. This provides an explicit perturbative example of infinite heat order in a four-dimensional ultraviolet-complete quantum field theory with a finite field content.

Seminar by Maria Olalla Olea Romacho (King's College, London)
2026-04-23 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: ‘Traces from Primordial Magnetogenesis’

Speaker: Maria Olalla Olea Romacho (King’s College, London)

Venue&Time: Red Room / 15:00

Abstract: Magnetic fields permeate the Universe across a wide range of scales, from galaxies and clusters to the most underdense regions of the cosmic web. Gamma-ray observations of TeV blazars suggest the presence of magnetic fields in intergalactic voids, where no efficient late-time astrophysical sources exist, pointing toward a possible primordial origin and a direct link to early-Universe physics. Primordial magnetic fields arise naturally in scenarios such as inflation or cosmological phase transitions. In this seminar, I present a multi-messenger perspective on their observational signatures. On the particle physics side, I discuss collider-motivated models of electroweak phase transitions, highlighting connections to blazar observations and stochastic gravitational-wave backgrounds. On the astrophysical side, I show how primordial magnetic fields enhance small-scale structure formation, leading to dense dark matter minihalos that boost indirect detection signals, and how they impact high-redshift observables probed by the James Webb Space Telescope.

Seminar: 'Collective vortex dynamics in strongly coupled superfluids'
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
Title: Collective vortex dynamics in strongly coupled superfluids
Speaker: Mikel Sanchez-Garitaonandia (University College Dublin)
Venue&Time: Red Room / 15:00

Abstract: Vorticity appears across a wide range of fluid phenomena, from the dynamics of classical fluids to quantum vortices in superfluids. In the latter case, vortices are topological defects that interact both with each other and with the surrounding medium. When a large number of vortices are present, it is natural to ask whether their collective behaviour can itself be described as a fluid, captured by an effective theory of vortex hydrodynamics. In this talk, I will explore the dynamics of many vortices in a strongly coupled superfluid with holography. By performing real-time simulations, I will investigate how the system approaches equilibrium and how its macroscopic behaviour compares with the predictions of vortex hydrodynamics. This allows to assess the range of validity of the hydrodynamic description and to understand how the system behaves beyond it.

Holo Club: (Quantum) evolution of de Sitter black holes
2026-04-28 11:30 - 12:30 | Blue Room, Instituto de Física Teórica (IFT) - C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Speaker: Muktajyoti Saha (ICTS-TIFR, Bengaluru)
Title: (Quantum) evolution of de Sitter black holes
Venue & Time: Blue Room / 11:30
Abstract:
I will discuss the evolution of charged black holes in asymptotically
de Sitter spacetime. These black holes evolve towards a thermal
equilibrium with the cosmological horizon. At very low temperatures
i.e. close to extremality, the semiclassical thermal description of
these black holes break down and quantum gravitational effects
dominate. Such quantum corrections can be effectively described in
terms of boundary Schwarzian modes localized at the edge of the large
near-horizon throat of these black holes. I will discuss how this
near-horizon effective theory changes the evolution of the black holes.
arXiv:2510.18035

Cosmology Journal Club
2026-04-28 14:00 - 15:00, 2026-05-05 14:00 - 15:00, 2026-05-12 14:00 - 15:00, 2026-05-19 14:00 - 15:00 | Discussion room 5th floor, C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 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

SPS Journal Club: 'Regge trajectories for UV completions of graviton scattering from polynomial boundedness'
2026-04-30 12:00 - 13:00 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Strings, Pheno and the Swampland (SPS) Journal Club. Every Thursday at 12:00 in the Red Room.
Bruno Bento (IFT) will present: ‘Regge trajectories for UV completions of graviton scattering from polynomial boundedness’

Venue & Time: Red Room / 12:00

Abstract: We study graviton scattering amplitudes. Assuming they are UV completed by a theory of weakly coupled massive higher spins, we demonstrate that the UV completion must possess infinitely many Regge trajectories, and thus they are forced to have a stringy spectrum. We extend and simplify a previous proof by some of us for open-string like states to the case of external gravitons. In the present new proof, we trace the need for infinitely many trajectories to the constraint of polynomial boundedness, ultimately tied to causality. We further present numerical results based on the stringy ansatz of Häring-Zhiboedov, which illustrates how single-trajectory-like solutions actually emerge as extremal solutions of numerical bootstrap. In our numerics, these trajectories curiously show up as numerically very large textit{sister} trajectories. We provide solid evidence that the solutions are spurious as they appear to admit a divergent limit for infinite ansatz size.

Pheno Journal Club
2026-04-30 12:00 - 13:00, 2026-05-21 12:00 - 13:00 | Grey Room 2, Instituto de Física Teórica, Madrid, Madrid, 28037, Spain
Every Thursday at 12:00 in Grey Room 2.

Seminar: 'Quantum computing for lattice gauge theories: from the Schwinger model to an SO(3) Quantum Link model'
2026-04-30 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: Quantum computing for lattice gauge theories: from the Schwinger model to an SO(3) Quantum Link model
Speaker: Bipasha Chakraborty (University of Southampton)
Venue&Time: Red Room / 15:00
Abstract: Quantum computing provides a promising framework for simulating strongly coupled gauge theories relevant to high-energy physics. In this talk, I will discuss quantum simulations of lattice gauge theories, focusing on the Schwinger model as a benchmark Abelian system and on a non-Abelian SO(3) gauge theory formulated as a quantum link model. I will outline gauge-invariant encodings and circuit implementations suitable for near-term devices, and comment on prospects for using quantum algorithms to study real-time dynamics and other regimes challenging for classical methods.

Seminar: 'Gravitational waves from phase transitions in the early Universe: sound waves and MHD turbulence'
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
Title: Gravitational waves from phase transitions in the early Universe: sound waves and MHD turbulence
Speaker: Alberto Roper Pol (Geneva)
Venue&Time: Red Room / 15:00
Abstract: Gravitational waves (GWs) can be produced by a first-order phase transition in the early Universe via the fluid perturbations induced in the primordial plasma by the expansion and collision of broken-phase bubbles. I will review the production of GWs by the anisotropic stresses of velocity and magnetic fields induced in a first-order phase transition and present recent developments on the analytical estimates and numerical simulations that address the stochastic GW background produced by acoustic motion (sound waves) and magnetohydrodynamic (MHD) turbulence. These GWs could be detectable by current and future GW detectors like LISA or PTA, potentially providing us with direct clean information of the physics at the high energies of the early Universe and probing beyond the Standard Model physics. In addition, the presence of magnetic fields at a phase transition leads to coupled non-linear fluid perturbations, described by MHD turbulence, that will impact the cosmological GW background. The study of these effects can be used to put constraints on primordial magnetic fields. These fields would evolve until present time and leave observable imprints in, for example, the CMB and in the cosmic voids of the large-scale structure of the Universe, allowing us to combine GW observations with other cosmological and astrophysical observations in a multi-messenger approach.

ML-AI Journal Club: 'Machine Learning in Astroparticle Physics'
2026-05-05 11:00 - 12:00
Title: ‘Machine Learning in Astroparticle Physics’
Speaker: Daniel Nieto Castaño (IPARCOS/UCM)
Venue&Time: Gray Room 2 / 11:00
Abstract: This seminar presents the motivation for employing machine
learning (ML) techniques to mitigate some experimental limitations
within the field of astroparticle physics. We will briefly review
selected applications across various detection domains, specifically
addressing astrophysical neutrinos, cosmic rays, and dark matter
candidates. Particular emphasis will be placed upon the analysis of
very-high-energy gamma-rays, illustrating how these ML frameworks are
increasingly integral to advancing current observational capabilities.

Holo Club: Holographic transport in anisotropic systems
2026-05-05 11:30 - 13:00 | Blue Room, Instituto de Física Teórica (IFT) - C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Title: Holographic transport in anisotropic systems
Speaker: Claire Moran (Utrecht University)
Venue&Time: Blue Room & Zoom / 11:30
Abstract:
Understanding transport in strongly coupled quantum systems remains a
central challenge across high-energy physics, condensed matter, and
quantum many-body theory. Of particular interest is systems exhibiting
anisotropy, where the anisotropy leads to a much richer transport
structure, with new transport coefficients emerging. The bulk
viscosity becomes especially subtle in anisotropic media, where it can
couple nontrivially to directional degrees of freedom and underlying
microscopic structure.
In this talk, I will discuss a recently developed holographic method
for computing the bulk viscosity in such systems. This approach
circumvents technical obstacles present in existing treatments and
yields analytic expressions. I will discuss the general structure of
the method, and highlight some applications of it.
Join Zoom Meeting
https://us02web.zoom.us/j/86014678323?pwd=[REDACTED]
Meeting ID: 860 1467 8323
Passcode: [REDACTED]

Seminar: 'Are string vacua connected?' by Ashoke Sen (ICTS-Infosys)
2026-05-06 11:00 - 12:00 | Blue Room, Instituto de Física Teórica (IFT) - C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Title: ‘Are string vacua connected?’

Speaker: Ashoke Sen (ICTS-Infosys)

Venue&Time: 11:00 / Blue Room

Abstract: String theory has many vacua. We shall examine the question of whether these vacua are connected from an experimentalist’s perspective.

Ashoke Sen is the ICTS-Infosys Madhava Chair Professor at the International Centre for Theoretical Sciences, Bengaluru.
His major honours include the ICTP Dirac Medal (2014), Breakthrough Prize in Fundamental Physics (2012), and the Infosys Prize in Mathematical Sciences (2009). He has also received the Padma Bhushan (2013) and the Padma Shri (2001), and is a Fellow of the Royal Society.

Quantum Information Journal Club: "Symmetry-protected topology and deconfined solitons in a multi-link Z2 gauge theory"
2026-05-06 11:30 - 12:30 | Gray Room 3, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Speaker: Enrico Calogero Domanti

Title: “Symmetry-protected topology and deconfined solitons in a multi-link Z2 gauge theory”

Venue&Time: Gray Room 3 / 11:30

Abstract: With the advent of quantum simulators, exploring exotic collective phenomena in lattice models with local symmetries and unconventional geometries is at reach of near-term experiments. Motivated by recent progress in this direction, we study a Z2 lattice gauge theory defined on a multi-graph with links that host Z2 gauge fields. Elementary Wilson loops along pairs of these bonds allow to identify a dynamical gauge-invariant flux, responsible for Aharonov-Bohm-like interference effects in the tunneling dynamics of charged matter residing on the vertices. We find inhomogeneous phases in which an ordered pattern of the gauge fluxes spontaneously breaks translational invariance. For an even number of links, this is caused by a phenomenon of dynamical Aharonov-Bohm caging, in which particles get trapped into portions of the lattice due to destructive interference. On the other hand, an odd number of links realizes a phenomenon analogous to the Peiels instability. In this case, long-range order is shown to coexist with symmetry protected topological order, which survives the quantum fluctuations of the gauge flux induced by an external electric field. Doping the system above half filling leads to the formation of topological soliton/anti-soliton pairs interpolating between different inhomogeneous orderings of the gauge fluxes. Quasiparticles carrying fractional charge and bound at the soliton centers emerge as deconfined degrees of freedom, as they can be arbitrarily separated without feeling a confining force, in spite of the long-range attractive interactions set by the small electric field on the individual integer charges.

Shannon's Corner Journal Club: "Zeros of the partition function and their algorithmic application"
2026-05-07 11:30 - 12:30
Speaker: Aram Harrow (MIT)
Title: “Zeros of the partition function and their algorithmic application”
Venue&Time: Gray Room 1 / 11:30
Abstract: “At high temperatures quantum systems generally lose
long-range order. We would expect that this makes them easier to
simulate. One way to understand this is through the analytic
properties of the partition function. Viewing Z(beta) = tr e^{-beta
H} as a function of a complex beta, its zeros turn out to tell us both
about phase transitions and about classical algorithms for estimating
Z(beta).”

SPS Journal Club: 'Calibration, fuzziness: new results on AdS vacuum decay'
2026-05-07 11:30 - 12:30
Strings, Pheno and the Swampland (SPS) Journal Club

Speaker: Vincent Menet (Università Milano Bicocca)

Title: ‘Calibration, fuzziness: new results on AdS vacuum decay’

Venue&Time: Red Room / 11:30

Abstract: Motivated by swampland conjectures, we study the stability of AdS type II supergravity vacua. In the literature, vacuum decay mediated by abelian D-branes has been discussed extensively, while this isn’t quite the case for both the D-brane bound states, and their non-abelian counterparts. In this context, we first present a tool to study large classes of D-branes and bound states, based on calibration theory, and then discuss vacuum decay mediated by weakly non-abelian D-branes. We illustrate our results by applying them to a few concrete AdS vacua.

Pheno Journal Club: "On the Inverse Problem in Effective Field Theory"
2026-05-07 12:00 - 13:00 | Grey Room 2, Instituto de Física Teórica, Madrid, Madrid, 28037, Spain
Jaime Fernandez Tejedor (IFT) will present “On the Inverse Problem in Effective Field Theory”.

Venue&Time: Gray Room 2 / 12:00

Abstract:

We show that the tree-level spectrum of heavy particles can be directly extracted from the Wilson coefficients of the corresponding effective field theory at low energies. This procedure is exact when the number of resonances is finite, and otherwise approximate. Our results are derived from a new class of analytic dispersion relations that depend nonlinearly on the scattering amplitude and apply to an exceedingly broad class of theories and kinematics.

Seminar by Christian Northe (Institute of Physics, Prague)
2026-05-07 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: Entanglement through topological interfaces in CFT revisited
Speaker: Christian Northe (Institute of Physics, Prague)
Venue&Time: Red Room / 15:00
Abstract: Present theoretical predictions for the entanglement entropy through topological defects are violated in numerical simulations of critical systems. In this talk, I discuss a paradigm shift in the preparation of reduced density matrices in the presence of topological defects, and emphasize the role of defect networks with which they can be dressed. Grouplike and duality defects are considered in detail for the Ising model, establishing agreement with all numerically found entanglement entropies. Since this new construction functions at the level of reduced density matrices, it accounts for topological defects beyond the entanglement entropy to other entanglement measures. The framework employs boundary conformal field theory techniques to implement the factorization of Hilbert space, which I recapitulate at the beginning of the talk and discuss its relation with the entanglement spectrum.

Seminar: 'Primordial Black Holes -- Positivist Perspective, Quantum Quiddity and Galaxy Genesis'
2026-05-11 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: ‘Primordial Black Holes — Positivist Perspective, Quantum Quiddity and Galaxy Genesis’
Speaker: Florian Kühnel, (TU Dortmund & LMU Munich)
Venue&Time: Red Room / 15:00
Abstract: Primordial black holes are black holes that may have formed in the early Universe. Their masses potentially span a range from as low as the Planck mass up to many orders of magnitude above the solar mass. This, in particular, includes those black holes recently discovered through gravitational waves, and (part of) these may conceivably be of primordial origin. After a general introduction on primordial black holes, I review the observational hints for their existence — from a variety of lensing, dynamical, accretion and gravitational-wave effects. As I will show, all of these (over 20) may be explained by a single and simple unified model, naturally shaped by the thermal history of the Universe. If time permits, I discuss how recent advances in our understanding of quantum effects in black holes impact PBHs. This prominently concerns deviations from Hawking radiation in the form of the memory-burden effect. Finally, I will elucidate on the role primordial black holes have on early galaxy and star formation.

Holo-Club: 'Emergence of Closed Universes in Holography'
2026-05-12 11:30 - 12:30 | Gray Room 3, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Speaker: Martin Sasieta (U. Berkeley)
Title: ‘Emergence of Closed Universes in Holography’
Venue&Time: Gray Room 3 / 11:30
Abstract:
I will present recent constructions of closed universes in AdS/CFT and AdS2 holography, and discuss some of the puzzles they pose.

DIFT Colloquium by Benjamin Grinstein (University of California, San Diego)
2026-05-13 15:30 - 16:00 | IFT Auditorium, Instituto de Física Teórica (IFT) - C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, Madrid, 28049,, Spain
Title: Buckets versus pipes: the neutron lifetime puzzle

Speaker: Benjamin Grinstein, University of California, San Diego

Date and time: 15:30h (CEST), Wednesday, May 13, 2026

Location: CFTMAT Auditorium

Abstract: A precise knowledge of the neutron lifetime is important because it serves as a fundamental input for Big Bang Nucleosynthesis (BBN) models, which predict the primordial abundances of light elements. It also enters in the determination of the Cabibbo mixing angle, crucial in testing the validity of the CKM theory of quark flavor, in understanding reactor neutrino detection rates and the behavior of matter in extreme environments like neutron stars. Precise experiments give very precise results, but the values determined differ by over 1% with high statistical significance depending on the technology used for the experiment. In this talk I will review this so-called “neutron lifetime puzzle” and some of the proposed solutions.

Join Zoom Meeting:
https://us02web.zoom.us/j/83038393323?pwd=[REDACTED]
Meeting ID: 830 3839 3323
Passcode: [REDACTED]
This event is related to the I+D+i project whose reference is CEX2020-001007-S, funded by MCIN/AEI/10.13039/501100011033. The topic is framed within the following research lines: Origin and composition of the universe: Astroparticles and Cosmology (Astro/Cosmo) & Particle Physics in the Standard Model and Beyond (BSM).

SPS Journal Club: 'Type IIB at Eight Derivatives: A Status Report'
2026-05-14 11:30 - 13:30 | IFT Seminar Room/Red Room, Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Strings, Pheno and the Swampland (SPS) Journal Club
Title: ‘Type IIB at Eight Derivatives: A Status Report’
Speaker: Raffaele Savelli (Dipartimento di Fisica & INFN, Università di Roma “Tor Vergata”)
Venue&Time: Red Room / 11:30
Abstract:
Knowledge of ten-dimensional superstring effective actions beyond the leading order in the derivative expansion is of intrinsic interest and plays a central role in many questions in string phenomenology. For Type IIB string theory, all the effective couplings are known at the four-point level, but a complete characterization of the eight-derivative effective action remains elusive.
In this seminar, I will discuss recent progress in deriving the five-point contact terms in sectors that mix gravity with the three-form flux and the axio-dilaton. I will present different approaches to this problem and emphasize the role of SL(2,Z) duality in constraining the structure of eight-derivative couplings and in revealing universal kinematical patterns. Finally, I will briefly comment on applications to lower-dimensional physics.
The talk is based on arXiv:2205.11530 and arXiv:2507.07934.

Seminar: 'Perturbative aspect of electroweak phase transitions in the Early Universe'
2026-05-14 12:00 - 13:00 | Blue Room, Instituto de Física Teórica (IFT) - C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, 28049,, Spain
Title: ‘Perturbative aspect of electroweak phase transitions in the Early Universe’

Speaker: Andrii Dashko (DESY)

Venue&Time: Blue Room / 12:00

Abstract: We present a study of the perturbative description of thermally driven electroweak phase transitions (EWPT) in the early universe. Focusing on strong first-order transitions, which are relevant for gravitational wave cosmology, we examine the dimensional reduction as a tool for a precise and systematic description focusing on the running of effective parameters within the effective field theory (EFT), and the impact of higher-dimensional operators. This allows us to assess the range of validity and theoretical uncertainties of the EFT approach. We demonstrate these results with applications to the Standard Model Effective Field Theory (SMEFT) and singlet extensions of the Standard Model, both of which can realize strong EWPT.

Pheno Journal Club
2026-05-14 12:00 - 13:00

Seminar: 'On the evidence for elastic interactions in the dark sector'
2026-05-18 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: ‘On the evidence for elastic interactions in the dark sector’
Speaker: Jose Beltrán Jiménez, University of Salamanca.
Venue & Time: Red Room / 15:00
Abstract: The increasing quality of cosmological data has revealed > some tensions among different probes that could be signalling the necessity of incorporating new physics into our cosmological model. One particularly intriguing possibility is the existence of elastic interactions between dark matter and dark energy. Not only do these interactions provide a natural mechanism to relief cosmological tensions, but there is also compelling observational evidence for them, to the extent that a detection could even be claimed. I wil review the potential of these scenarios in relation to the cosmological tensions and discuss distinctive signatures that can be probed with future data, thus providing a smoking gun for these interactions.

Quantum Information Journal Club: 'Optimal strategies for near-term simulation of fermionic systems with scalable local fermion-to-qubit mappings'
2026-05-20 11:30 - 12:30
Title: ‘Optimal strategies for near-term simulation of fermionic systems with scalable local fermion-to-qubit mappings’

Speaker: Manuel G. Algaba

Venue&Time: Gray Room 3 / 11:30

Abstract: Quantum simulation of interacting fermions remains one of the most compelling applications of quantum computing, but its practical realization depends on more than the asymptotic promise of fault-tolerant quantum algorithms. To bridge the gap with current NISQ devices, we derive a strategy for growing the corresponding code distance of local fermion-to-qubit mappings, which is otherwise fixed. Building upon the extended error detection properties of these mappings we present a quantum error mitigation (QEM) technique tailored for fermionic systems which outperforms other widely used techniques such as Post-selection, Virtual Distillation, and Probabilistic Error Cancellation in regimes of practical interest. We then study the performance of different combinations of QEM and fermion-to-qubit mappings and identify the best combination of mapping and QEM. This study enables us to derive minimal hardware requirements for the simulation of Fermi-Hubbard models of various sizes in near-term devices.
