Gravitational-Wave Primordial Cosmology

Europe/Paris
Description

This virtual workshop gathers a group of international experts on gravitational-wave primordial cosmology. It will take place on zoom, over three half-days on May 17th-19th, from 2pm to 6.30pm CEST.

The main goal of the workshop is to critically review recent progress about the potential of gravitational waves to probe inflation on small scales, but related aspects like preheating, primordial black holes, phase transitions and the thermal history of the universe will also be discussed. A particular focus will be given to the observability of the various properties of the stochastic gravitational wave background, including its spectral shape and polarisation, and their implications for the inflationary mechanism and field content. Cross-correlations with other observables will also be discussed, together with methods of data analysis and prospect for detection.

But this workshop will not be limited to a review of recent progress. It also aims at collectively identifying important open questions and assessing the potential of discovery of gravitational wave astronomy for primordial cosmology. For this, in addition to invited presentations, lasting 30 minutes each, time will be left for informal discussions, and the workshop will end with a summary of the important issues to address in this field.

There is no registration fee, but registration through indico is compulsory.


Speakers include:

  • Matteo Braglia
  • Chiara Caprini
  • Sébastien Clesse
  • Ema Dimastrogiovanni
  • Guilhem Domenech
  • Matteo Fasiello
  • Daniel Figueroa
  • Ryusuke Jinno
  • Azadeh Maleknejad
  • Subodh Patil
  • Shi Pi
  • Mauro Pieroni
  • Antonio Riotto
  • Lorenzo Sorbo
  • Spyros Sypsas
  • Gianmassimo Tasinato
  • Caner Ünal
  • Lukas Witkowski

Organisers: Sébastien Renaux-Petel, Jacopo Fumagalli, Sebastian Garcia-Saenz, Sadra Jazayeri, Lucas Pinol, Lukas Witkowski

This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme under grant agreement No 758792, project GEODESI.

 

Participants
  • Adam Solomon
  • Alba Kalaja
  • Alberto Mangiagli
  • Alberto Roper Pol
  • Alessandro Parisi
  • Alex Jenkins
  • Alexander Criswell
  • Alfredo Delgado Miravet
  • Alireza Talebian
  • Alvise Raccanelli
  • Amaury MICHELI
  • Ameek Malhotra
  • Ana Achucarro
  • Ana Caramete
  • Anastasiia Filimonova
  • Andrea Maselli
  • Andrei Parnachev
  • Andrew Gow
  • Angelo Caravano
  • Angelo Ricciardone
  • Anindya Dey
  • Anna Negro
  • Anna Ritz-Zwilling
  • Anson Chen
  • Antonio Riotto
  • Ashley Wilkins
  • Asuka Ito
  • Atsushi Naruko
  • Avery Tishue
  • Ayan Kumar Ghosh
  • Azadeh Maleknejad
  • Azrul Sulaiman Karim POHAN
  • Banafsheh Shiralilou
  • Batool Ashtari
  • Berrie Giebels
  • Bhuvan Agrawal
  • Borna Salehian
  • Brahim Lamine
  • Caner Ünal
  • Carlo Contaldi
  • Carlo Schimd
  • Carlos Duaso Pueyo
  • Carlos Martins
  • Carlos Tamarit
  • Carmelita Carbone
  • Chiara Animali
  • Chiara Caprini
  • Chinmay Gandevikar
  • christophe ringeval
  • Cornelius Rampf
  • Cristian Joana
  • Cristóbal Zenteno
  • Cédric Deffayet
  • Daniel Cutting
  • Daniel Eduardo Amaya Matamoros
  • Daniel G. Figueroa
  • Daniele Bertacca
  • Darshan Kumar
  • David Andriot
  • David Kniazevas
  • David Langlois
  • David Stefanyszyn
  • David Wands
  • Deanna Hooper
  • denis comelli
  • Denis Werth
  • Diederik Roest
  • Diego Rubiera-Garcia
  • Disrael Cunha
  • Dominik Schwarz
  • Dong-Gang Wang
  • Ekaterina Pozdeeva
  • Eleftherios Malandris
  • Elham Nazari
  • Elisa Ferreira
  • Ema Dimastrogiovanni
  • Emir Gumrukcuoglu
  • Encieh Erfani
  • Enis Belgacem
  • Enrico Morgante
  • Enrico Pajer
  • Ester Ruiz Morales
  • Eugeny Babichev
  • Evangelos Sfakianakis
  • Fabio van Dissel
  • Fabrizio Rompineve
  • Fateme SHOJAEI ARANI
  • Fazlollah Hajkarim
  • Fereshteh Felegary
  • Filippo Vernizzi
  • Florent Robinet
  • Francesco Muia
  • François Rincon
  • Gabriele Franciolini
  • Ganesh Subramaniam
  • Gansukh Tumurtushaa
  • George Zahariade
  • Gianmassimo Tasinato
  • Giorgio Orlando
  • Giovanni Otalora
  • Giulia Cusin
  • Giulia Gubitosi
  • Gonzalo Palma
  • Gregoire Pierra
  • Guillem Domenech
  • Guillermo Ballesteros
  • Haris Kunjumuhammed
  • Hassan Firouzjahi
  • Heling Deng
  • Hidetoshi Omiya
  • Houri Ziaeepour
  • Ilia Musco
  • Ioannis Soranidis
  • Ippei Obata
  • Ira Wolfson
  • Ivonne Zavala
  • Jacopo Fumagalli
  • Javier Olmedo
  • Jerome Quintin
  • Jinsu Kim
  • Joanes Lizarraga
  • Joaquin Diaz-Alonso
  • Joe Silk
  • Joonas Hirvonen
  • Jorinde van de Vis
  • Jose Juan Blanco-Pillado
  • José Carlos Olvera Meneses
  • João Rosa
  • Julien Lavalle
  • Julián Rey
  • Kai Schmitz
  • Kaloian Lozanov
  • Karim Noui
  • Karsten Jedamzik
  • Katarina Martinovic
  • Katy Clough
  • Kelly Weerman
  • Kevin Gonzalez-Quesada
  • Konstantinos Dimopoulos
  • Krzysztof Turzyński
  • Kwinten Fransen
  • Laura Iacconi
  • Lazaros Souvaitzis
  • Lijing Shao
  • Lorenzo Pizzuti
  • Lorenzo Sorbo
  • Luca Caloni
  • Lucas Pinol
  • Luigi Pilo
  • Luiz Filipe Guimarães
  • Lukas Witkowski
  • Macarena Lagos
  • Mahdiyar Noorbala
  • Manjeet Kaur
  • Marc Lilley
  • Marco Antonio Merchand Medina
  • Marco Scalisi
  • Marek Lewicki
  • Mariana Carrillo Gonzalez
  • Martina Muratore
  • Massimiliano Maria Riva
  • Matteo BARSUGLIA
  • Matteo Braglia
  • Matteo Fasiello
  • Mauro Pieroni
  • Mayukh Gangopadhyay
  • Miguel Llamas Lanza
  • Miguel Zilhao
  • Ming-Feng Ho
  • Mohamed Younes Sassi
  • Mohammad Ali Gorji
  • Mohammad Arab
  • Mohammad Hossein Namjoo
  • Mohd Sirtaz
  • Mojtaba Najafizadeh
  • Morteza Khamedi
  • Mrunali Gaijan
  • Naoki Seto
  • Nick Samaras
  • Nicola Bartolo
  • Nikolaos Karnesis
  • Nilanjandev Bhaumik
  • Nils Nilsson
  • Nooshin Alinezhadi
  • Ogan Ozsoy
  • Oksana Iarygina
  • Oliver Gould
  • Paolo Campeti
  • Paolo Creminelli
  • Patrick Valageas
  • Pawan Kumar Gupta
  • Pawel Mazur
  • Pedro Fernandes
  • Peera Simakachorn
  • Petra Tang
  • Philip Soerensen
  • Philippa Cole
  • Philippe Simonis
  • Pietro Conzinu
  • postma marieke
  • Rajeev Kumar Jain
  • RATHUL NATH RAVEENDRAN
  • Renate Meyer
  • Ricardo Zambujal Ferreira
  • Riccardo Della Monica
  • Robert Rosati
  • Rocco Rollo
  • Rodrigo Calderón
  • Rohoollah Mohammadi
  • Ruth Gregory
  • Ryusuke Jinno
  • Saboura sadat Zamani
  • Sachiko Kuroyanagi
  • Sadra Jazayeri
  • Sahil Ugale
  • Salomeh Khoeini-Moghaddam
  • Samuel Sanchez Lopez
  • Sang Pyo Kim
  • Santiago Jaraba
  • Sayantan Choudhury
  • Scott Melville
  • Sebastian Cespedes
  • Sebastian Garcia-Saenz
  • Sebastien Clesse
  • shabeeb Alalawi
  • Shahram Khosravi
  • Shi Pi
  • Shichao Wu
  • Shinji Mukohyama
  • Shu-Di Yang
  • Silvia Gasparotto
  • Simeon Bird
  • Sina Hooshangi
  • Sobhan Kazempour Ishka
  • Sofia Canevarolo
  • Sonia Paban
  • Spyros Sypsas
  • Stavros Katsanevas
  • Stavros Mougiakakos
  • Stefan Strub
  • Subodh Patil
  • Sébastien Renaux-Petel
  • T.S.Sachin Venkatesh
  • Takahiro Terada
  • Tao Xu
  • Theodoros Pailas
  • Theodoros PAPANIKOLAOU
  • Thomas Kite
  • Timm Wrase
  • Tomislav Prokopec
  • Torben Frost
  • Tuomas Tenkanen
  • Valerie Domcke
  • Valerio De Luca
  • valerio ferroni
  • Valery Zhdanov
  • Vasilis K. Oikonomou
  • Vikas Aragam
  • Ville Vaskonen
  • Vincent Vennin
  • Viola Sordini
  • Vuk Mandic
  • Wei-Tou Ni
  • Wolfram Ratzinger
  • Xingang Chen
  • Yaser Tavakoli
  • Yichao Hu
  • Yong Tang
  • Yong Xu
  • Yun-Long Zhang
  • Yutong He
  • Zakaria BELKHADRIA
Contact
    • 1
      Welcome
      Speaker: Sébastien Renaux-Petel (IAP-CNRS)
    • 2
      Cosmology with LISA
      Speaker: Chiara Caprini
    • 3
      Measuring the net circular polarization of the stochastic gravitational wave background with interferometers
      Speaker: Lorenzo Sorbo
    • 4
      Stochastic Gravitational Wave Backgrounds (SGWB) characterization with LISA

      In this talk I will discuss Stochastic Gravitational Wave Backgrounds (SGWB) characterization with LISA. After a general introduction on SGWB detection, I will explain the peculiar features of LISA with a focus on the response function and on the noise spectrum. The core of my talk will be the presentation of two different methods for model independent SGWB frequency reconstruction:
      - The so-called ``binning method'' (1906.09244, 2009.11845) based on the idea of approximating the signal with a piecewise-defined function where each sub-function is a power law.
      - A more recent method (2004.01135) based on principal components analysis.
      The problem of component separation to disentangle a cosmological SGWB from astrophysical foregrounds is addressed in both cases.

      Speaker: Mauro Pieroni
    • 5
      Open discussion
    • 4:10 PM
      Break
    • 6
      Gauge Fields in Inflation, Origin of Matter, and Gravitational Waves

      Modern cosmology inevitably involves particle physics beyond the Standard Model to explain long-standing puzzles: the origin of matter asymmetry, nature of dark matter and cosmic inflation. In this talk, I will explain that gauge fields in inflation can possibly solve and relate these seemingly unrelated mysteries of modern cosmology. As a smoking gun, this setup has robust observable signatures for the gravitational background to be probed by future CMB missions and laser interferometer detectors.

      Speaker: Azadeh Maleknejad
    • 7
      Probing the Early Universe Particle Content with Primordial Messengers

      Some of our best ideas on early universe physics are about to be put to the test by an unprecedented array of cosmological probes. The data these will collect span a vast range of scales, from the CMB to large scale structure, from pulsar timing arrays all the way to laser interferometers. This combined wealth of new information holds the potential to transform not just our understanding of cosmology, but also particle physics. Probing the earliest accessible epoch, the accelerated expansion known as inflation, is absolutely crucial: inflation can provide a cosmological portal to otherwise inaccessible energy scales. This is the “cosmological collider” idea. The spectacular success of the inflationary paradigm in explaining the origin of cosmic structure demands that we tackle a number of compelling questions still in need of an answer:
      - what is the energy scale of inflation?
      - what fields were active during inflation?
      In this talk I will review recent progress on the inflationary field content focussing on an effective theory approach. I will also highlight key observables, starting with primordial gravitational waves, and discuss the prospect for detection.

      Speaker: Matteo Fasiello
    • 8
      Testing inflation with small-scale anisotropies

      Inflation predicts a stochastic background of gravitational waves. In this talk I will discuss how anisotropies in the gravitational wave energy density can be a powerful tool in characterizing the inflationary GW background and potentially distinguishing it from backgrounds due to other sources.

      Speaker: Ema Dimastrogiovanni
    • 9
      Open discussion
    • 10
      Probing gravitational waves using spectral distortions

      CMB anisotropies probe primordial gravitational wave backgrounds of frequencies between 10^{-18} and 10^{-15} Hz. Pulsar timing arrays begin to be sensitive to backgrounds starting in the nano-hertz regime, seemingly leaving an approximately six decade gap in frequency coverage. This talk will discuss how spectral distortions of the CMB covers this gap in a meaningful way, and discuss various phenomenological consequences for a variety of beyond the standard model scenarios, including low scale (dark sector) phase transitions, cosmic strings and ultra-light axions.

      Speaker: Subodh Patil
    • 11
      Features in the stochastic gravitational wave background from two-field inflationary models.
      Speaker: Matteo Braglia
    • 12
      Oscillations in the stochastic gravitational wave background from small-scale features
      Speaker: Lukas Witkowski
    • 13
      Observing primordial GWs from excited states
      Speaker: Spyros Sypsas
    • 14
      Open discussion
    • 4:00 PM
      Break
    • 15
      Probing the Physics of Inflation with Gravitational Wave Experiments
      Speaker: Gianmassimo Tasinato
    • 16
      Imprints of Primordial Non-Gaussianity on Gravitational Wave Spectrum

      I will talk about the imprints of small, mild and large primordial local NG in density perturbations on the induced GW spectrum.

      Speaker: Caner Ünal
    • 17
      Are induced GWs gauge dependent?
      Speaker: Guillem Domènech
    • 18
      Open discussion
    • 19
      NANOGrav 12.5-yr result and induced gravitational waves

      I will briefly review the properties of SGWB induced by the scalar perturbation, as well as its connection to the primordial black holes (PBHs). NANOGrav reported the discovery of a common-spectrum process of the time residuals in their 12.5-yr data set of pulsar timing array, which might be the first detection of nano-hertz SGWB. Based on the recent developments on the spectral shape of SGWB, I will show that this signal could be connected to the planet-mass PBH candidates found by OGLE recently, if there is a dust-like stage prior to the radiation dominated era.

      Speaker: Shi Pi
    • 20
      Primordial Nano Black Holes
      Speaker: Antonio Riotto
    • 21
      Primordial Black Holes: gravitational-wave signatures and possible contribution to the dark matter

      The detection of gravitational-waves from binary black hole mergers has rekindled the idea that primordial black holes may have formed in the early Universe. I will review some recent developments in the field of primordial black holes: formation mechanisms, mass function, astrophysical limits, possible contribution to the Dark Matter and links to the Baryogenesis. I will particularly focus on their gravitational-wave signatures: merging rates, explanation of recent LIGO/Virgo events (GW190521, GW190815, GW190425), subsolar black hole searches, stochastic gravitational-wave backgrounds and continuous waves or high-frequency GW detectors as a probe of planetary-mass primordial black holes.

      Speaker: Sebastien Clesse
    • 22
      Open discussion
    • 4:00 PM
      Break
    • 23
      Deformation of the gravitational wave spectrum by density perturbations

      In recent years, the possibility of having large density perturbations at high wavenumbers has been actively studied, especially in the study of primordial black holes (PBHs). In this presentation, we point out that such density perturbations affect any pre-existing gravitational wave (GW) spectrum through CMB-like effects. Since GWs produced in the early universe propagate through the density perturbations before reaching the observer, GWs coming from each direction experience different evolution depending on the density perturbations. As a result, the observed (directionally averaged) GWs generally have a deformed spectrum compared to the original one. Therefore, by carefully comparing the observed spectrum with the theoretical GW spectrum at the time of production, we may be able to indirectly observe density perturbations at high wevenumbers. In this presentation, we explain how this effect shows up and estimate the maximum expected impact on the GW spectrum, taking into account the latest bound on density perturbations from PBH searches.

      Speaker: Jinno Ryusuke
    • 24
      Probing the 'primordial dark ages’ with gravitational waves. Implications for reheating.
      Speaker: Daniel Figueroa
    • 25