Cosmology 100 Years After Lemaître’s Expanding Universe: Open Questions and New Frontiers
a Focus Meeting at the XXXIII International Astronomical Union General Assembly, August 2027, Rome, Italy
Abstract and grant applications due January 15th, 2027: visit https://iaurome2027.org to submit, this is FM-6
ABSTRACT
In 1927 Georges Lemaître first established the linear relation between recession velocity and distance, marking the theoretical discovery of the expansion of the Universe. The 2027 Lemaître Focus Meeting commemorates the centenary of this groundbreaking achievement while exploring the scientific questions that continue to shape modern cosmology.
Today, some of the most pressing challenges include the Hubble tension, the nature of black holes and spacetime singularities, the role of gravitational waves as cosmological probes, and the status of cosmic inflation.
By bringing together experts in observational cosmology, gravitational-wave astronomy, black-hole physics, and quantum gravity, the meeting will provide a unique interdisciplinary forum to assess how forthcoming observations and theoretical advances can jointly test the limits of the standard cosmological model.
Following the spirit of Georges Lemaître's scientific legacy, the Focus Meeting aims to strengthen the dialogue between theory and observation while identifying concrete pathways toward resolving some of the most fundamental open questions in cosmology.
The legacy of Georges Lemaître: historical overview
The legacy of Georges Lemaître: impact on modern cosmology
Cosmic expansion and the Hubble tension: observational perspective
Cosmic expansion and the Hubble tension: theoretical perspective
Space-time singularities and quantum gravity: future probes
Space-time singularities and quantum gravity: theoretical perspective
Piero Benvenuti (University di Padova, Italy; IAU commission C3, division B and C)
Wendy L. Freedman (University of Chicago, USA; IAU division J)
P. Gabriele Gionti, S.J. (Vatican Observatory, Vatican; IAU division D and J)
Adam D. Hincks (University of Toronto, Canada)
Michael S. Turner (University of Chicago, USA; IAU division J)
Piero Benvenuti (University di Padova, Italy; IAU commission C3, division B and C)
Wendy L. Freedman (University of Chicago, USA; IAU division J)
P. Gabriele Gionti, S.J. (Vatican Observatory, Vatican; IAU division D and J)
Adam D. Hincks (University of Toronto, Canada)
Michael S. Turner (University of Chicago, USA; IAU division J)
Elia Battistelli (Università La Sapienza, Italy)
Ileana Chinnici (INAF, Italy; IAU division C)
Ruth Durrer (Université de Genève, Switzerland)
George Ellis (University Cape Town ,South Africa; IAU division F and J)
Macarena Alejandra Lagos Urbina (Universidad Andrés Bello, Chile; IAU division D)
Dominique Lambert (University of Namur, Belgium)
Jia Liu, (Kavli IPMU, University of Tokyo, Japan)
Jean-Pierre Luminet (Laboratoire d'Astrophysique de Marseille, France; IAU commission C3, division C, D and J)
Priyamvada Natarajan (Yale University, USA; IAU division A, C, D and J)
Hiranya V. Peiris (University of Cambridge, UK)
Costantino Sigismondi (Icranet, Italy; IAU commission C3)
P. Gabriele Gionti, S.J. (Vatican Observatory, Vatican; IAU division D and J)
Matteo Galaverni (Vatican Observatory, Vatican; IAU division D and J)
Massimo Bianchi (Università di Roma “Tor Vergata”)
Sergio Cacciatori (Università dell’Insubria)
Pasquale Mazzotta (Università di Roma “Tor Vergata”)
Fabio Scardigli (Politecnico di Milano)
The following are important deadlines:
- Abstract submission and grant application open: July 20th, 2026
- Abstract submission and grant application deadline: January 15th, 2027 (23.59 CET)
- IAU GA early registration deadline: March 5th, 2027 (23.59 CET)
- IAU GA normal registration deadline: June 30th, 2027 (23.59 CET)
- Focus Meeting: 11-12 August 2027
Session plan:
Each of the six 90 minute sessions will begin with invited talk to appropriately set the scene (25+5 minutes) followed by contributed and invited talks (12+3 minutes).
Program:
TBD
CONTACT
For any inquiries regarding the IAU Focus Meeting 6, please contact the Local Organizing Committee:
All participants are expected to comply with the International Astronomical Union (IAU) Code of Conduct, which promotes professional behavior, mutual respect, inclusivity, and a harassment-free environment. Please review the document below.
IAU CODE OF CONDUCT
All participants must complete the official registration process before attending the meeting. Please consult the registration page below for information on fees, deadlines, and participation requirements.
REGISTRATION PAGE
Specola Vaticana
Vatican Observatory
00120 Stato Città del Vaticano
