ICCUB School 2023: Primordial Black Holes

Europe/Madrid
UB Physics Faculty

UB Physics Faculty

Martí i Franquès, 1, 11 08028 Barcelona
Description

ICCUB School

Primordial Black Holes (PBHs), arguably the most economical candidates for Dark Matter, have recently fostered an intense debate within the scientific community. As a result of that, in recent years, there has been a better understanding of their formation, abundance, and signatures.


The aim of the school is to bring together latest key developments on PBHs into a pedagogical and coherent picture. The focus of the school is on PBHs generated from rare inflationary perturbations.
Their formation, statistical distribution and signatures are going to be core topics of the school.


This school is intended for PhD students and young postdocs that have general knowledge of cosmological perturbations theory. Nevertheless, we also provide a pre-school lecture on basics concepts of perturbations theory.


Lectures start every morning at 9:30 and finish at 18:00 (with small variations). Finally, there is also a scheduled time for selected talks from the students.

Limited number of places.

Lecturers

  • Ana Achucarro (Leiden University, Netherlands)

    "Enhancement mechanisms for cosmological perturbations"
     
  • Guillem Domènech (Leibniz University, Germany)

    “Gravitational waves signatures of primordial black holes”
     
  • Albert Escrivà (Nagoya University, Japan)

    "Primordial Black Holes formation, theory and simulations"
     
  • Natalia Korsakova (APC, France)

    “LISA capabilities in the context of PBH physics”
     
  • Florian Kuhnel (Ludwig-Maximilians-Universitaet, Germany)

    "Constraints on Primordial Black Holes"
     
  • Ravi Sheth (University of Pennsylvania, USA)

    "The statistics of Primordial Black Holes"

 

Pre-school

  • Jaume Garriga (University of Barcelona and ICCUB)

    “Basics of cosmological perturbation theory”

 

In addition, there will be a distinguished guest seminar:

Misao Sasaki (Kavli Institute for the Physics and Mathematics of the Universe, Japan)

“PBHs from highly non-Gaussian tails of the probability distribution”

 

When

26th-30th June, 2023 from 9:30Am to 6:30PM

 

Scientific Organizing Committee

  • Jacopo Fumagalli (Universitat de Barcelona and ICCUB)
  • Cristiano Germani (Universitat de Barcelona and ICCUB) - Chair
  • Carlos Sopuerta (ICE-CSIC/IEEC)

Local Organizing Committee

  • Anna Argudo (ICCUB)
  • Esther Pallarés (ICCUB)

 

 

Acknowledgements

This event is part of the grant, Institut de Ciències del Cosmos, CEX2019-000918-M funded by MCIN/AEI/10.13039/501100011033.

This event is part of the grant Spanish Contribution to LISA: Instrument Development and Scientific Exploitation, PID2019-106515GB-I00, funded by MCIN/AEI/10.13039/501100011033.

Participants
  • Adolfo Hilario-Garcia
  • Adrián Palomares
  • Aichen Li
  • Albert Sanglas
  • Ana Alexandre
  • António Torres Manso
  • Catalina-Ana Miritescu
  • Daniel Marin Pina
  • Devanshu Sharma
  • Diego Cruces
  • Enrique Gaztanaga
  • Ethan Milligan
  • Giorgio Mentasti
  • Itziar Aldecoa Tamayo
  • Jahmall Matteo Bersini
  • Jan Tränkle
  • Joseph Jackson
  • Marc Andrés Carcasona
  • Mateo Pascual
  • Mickael Komendyak
  • Musfar Kozhikkal
  • Nataliya Porayko
  • Ornella Juliana Piccinni
  • Paulo Ferraz
  • Pritha Bari
  • Raphael Picard
  • Sofie Ried
  • Vadim Briaud
  • Valentin Thoss
    • 08:30
      Registration
    • 09:15
      Welcome
    • 1
      Pre-school: Basics of cosmological perturbation theory
      Speaker: Jaume Garriga (ICCUB)
    • 11:30
      Break
    • 2
      Constraints on primordial black holes
      Speaker: Florian Kuhnel (Ludwig-Maximilians-Universitaet)
    • 13:00
      Lunch break
    • 3
      Enhancement mechanisms for cosmological perturbations
      Speaker: Ana Achucarro (Leiden University)
    • 16:30
      Break
    • 4
      Constraints on primordial black holes
      Speaker: Florian Kuhnel (Ludwig-Maximilians-Universitaet)
    • 5
      Enhancement mechanisms for cosmological perturbations
      Speaker: Ana Achucarro (Leiden University)
    • 11:30
      Break
    • 6
      Constraints on primordial black holes
      Speaker: Florian Kuhnel (Ludwig-Maximilians-Universitaet)
    • 13:00
      Lunch Break
    • Selected Talks
      Conveners: Cristiano Germani (UB physics), Jacopo Fumagalli (ICCUB - Universitat de Barcelona)
      • 7
        Numerical simulations of stochastic inflation using importance sampling

        Primordial black holes are expected to form from large, but rare, cosmological fluctuations in the tail of the probability distribution arising from inflation. I will present how importance sampling can be used to efficiently investigate the far, numerically expensive, probability tail of these fluctuations, finding non-perturbative deviations from Gaussianity. This is done by solving the first-passage time problem in the Langevin processes to find the distribution of the local duration of inflation in e-folds. By the stochastic-$\delta N$ formalism, these are related to the curvature perturbation at the end of inflation. What previously would take supercomputers weeks, or in principle even years, can be done in hours with just a single CPU using this approach.

        Speaker: Joseph Jackson (University of Portsmouth)
      • 8
        Towards a non-perturbative description of inflation

        In recent years, primodrial black holes (PBHs), i.e. black holes produced in the very early universe, have attracted much attention because of their important cosmological consequences. One of the mechanisms that can produce PBHs is the collapse of superhorizon large density inhomogeneities whenever they enter the horizon. These large inhomogeneities can be generated during inflation, reason why a non-perturbative (in terms of the amplitude of the inhomogeneities) description of inflation is of crucial importance in order to correctly describe the abundance of PBHs. In this talk I will explore some of the attempts to achieve such a non-perturbative description of inflation such as the \deltaN or stochastic formalism and their difficulties.

        Speaker: Diego Cruces (ICCUB)
      • 9
        Balancing the medium response in minimal warm inflation

        Axion-like inflation models have for long been discussed as the radiative corrections that spoil many single-field models are avoided by virtue of its shift symmetry. In addition, the inflaton can generically have an axion-like coupling to non-abelian gauge bosons. It has been shown that this interaction automatically induces a non-diluting thermal bath during inflation leading to a warm-inflation scenario. The peculiarity of a medium response with two physical origins, vacuum and thermal dynamics, leads into interesting phenomenology to describe the early and later stages of inflation. In this work we will study the conditions where these models satisfy Planck constrains, and possibly generate the amplification of scalar and tensor perturbations at the later stages of inflation whenever the thermal contribution dominates.

        Speaker: António Torres Manso (Universidad Granada)
      • 10
        New method to detect continuous gravitational waves from inspiraling light primordial black holes

        Primordial black holes can span a large range of masses depending on their time of formation. In particular, they can have subsolar masses and form binary systems in an efficient way. The inspiral phase can last for long periods of time (from hours to years) with a slow increase of frequency and, therefore, these signals are well suited to be searched with continuous gravitational waves methods. We present a new method based on the band sampled data (BSD) framework to specifically target this kind of signals. Additionally, we show an estimation of the sensitivity of the search and the computational cost associated to it.

        Speaker: Marc Andrés Carcasona (IFAE)
      • 11
        Superradiant pion clouds around primordial black holes

        We show that highly spinning primordial black holes of mass M ∼ 10^12 kg, potentially born in a matter-dominated era after inflation, can produce clouds of pions in their vicinity via the su- perradiant instability, with densities up to that of nuclear matter. We discuss the electromagnetic signatures of this process, via neutral pion decay and charged pion annihilation into photons, com- puting in particular their contribution to the isotropic gamma-ray background. This allows us to place upper bounds on the abundance of such primordial black holes that are comparable to the ones obtained from Hawking evaporation. We also discuss the possibility of directly observing such clouds in high-redshift superclusters.

        Speaker: Paulo Ferraz (University of Coimbra)
      • 12
        Diffuse emission from black hole remnants

        At the end of its evaporation, a black hole may leave a remnant where a large amount of information is stored. We argue that the existence of an area gap as predicted by loop quantum gravity removes a main objection to this scenario. Remnants should radiate in the low-frequency spectrum. We model this emission and derive properties of the diffuse radiation emitted by a population of such objects. We show that the frequency and energy density of this radiation, which are measurable in principle, suffice to estimate the mass of the parent holes and the remnant density, if the age of the population is known.

        Speaker: Mateo Pascual (Western University, London)
    • 16:30
      Break
    • 13
      Constraints on primordial black holes
      Speaker: Florian Kuhnel (Ludwig-Maximilians-Universitaet)
    • 14
      PBHs from highly non-Gaussian tails of the probability distribution

      It has now become fully realized that the PBH formation depends crucially on the tails of the probability distribution function (PDF) of the curvature perturbation. In this talk, I will review some recently proposed models of inflation in which highly non-Gaussian tails appear in the PDF that can only be computed non-perturbatively, and discuss their implications.

      Speaker: Misao Sasaki (IMPU)
    • 10:30
      Break
    • 15
      The statistics of primordial black holes
      Speaker: Ravi Sheth (University of Pennsylvania)
    • 13:00
      Lunch Break
    • Selected Talks
      Convener: Carlos Sopuerta (CSIC)
      • 16
        The ultraviolet limit of the power spectrum and Lagrangian perturbation theory

        Understanding the non-linear evolution of Large Scale Structure (LSS) is a key challenge in contemporary cosmology. To this end, it is important to combine both numerical simulations and analytical approaches, such as perturbation theory of LSS. Recently, it has been understood that the power spectrum in a cold dark matter dominated Universe can be investigated via an expansion in inverse powers of the wavenumber. In this talk, I will discuss various aspects of this novel expansion. In particular, I will show how it relates to Lagrangian perturbation theory and use it to derive powerful constraints on the structure of the effective field theory of LSS.

        Speaker: Jahmall Matteo Bersini (Kavli IPMU)
      • 17
        Primordial black holes as dark matter candidates in braneworld cosmology

        In this talk I will present my current research on primordial black holes in (4+1) dimensional models. I will discuss how black hole properties - such as temperature, accretion rate and evaporation - change when one introduces an extra dimension. We are currently studying how these changes affect the range of masses in the dark matter window (f_PBH~1) and other observational signatures.

        Speaker: Itziar Aldecoa Tamayo (University of Sussex / ICCUB)
    • 15:00
      Break
    • 18
      Primordial black holes formation, theory and simulations
      Speaker: Albert Escrivà (Nagoya University)
    • 19
      Gravitational waves signatures of primordial black holes
      Speaker: Guillem Domènech (Leibniz University)
    • 11:30
      Break
    • 20
      The statistics of primordial black holes
      Speaker: Ravi Sheth (University of Pennsylvania)
    • 13:00
      Lunch Break
    • 21
      LISA capabilities in the context of PBH physics
      Speaker: Natalia Korsakovoa (APC)
    • 16:00
      Break
    • 22
      Primordial black holes formation, theory and simulations
      Speaker: Albert Escrivà (Nagoya University)
    • 23
      Gravitational waves signatures of primordial black holes
      Speaker: Guillem Domènech (Leibniz University)
    • 11:30
      Break
    • 24
      LISA capabilities in the context of PBH physics
      Speaker: Natalia Korsakova (APC)
    • 13:00
      Lunch Break
    • 25
      The statistics of primordial black holes
      Speaker: Ravi Sheth (University of Pennsylvania)
    • The latest updates from the pulsar timing array community
      Convener: Nataliya Porayko (Milano Bicocca University)
    • 16:45
      Break
    • 26
      LISA capabilities in the context of PBH physics
      Speaker: Natalia Korsakova (APC)