CA23130 - Bridging high and low energies in search of quantum gravity (BridgeQG)

WG2 online meeting
2025-11-27 15:00 - 16:00 (Europe/Rome)
Zoom link sent by email

WG3 Focused discussion I
2025-11-28 14:00 - 15:30
Theme: What questions do quantum reference frames address, and when are the approaches valid?
Panelists: Leon Loveridge (Uni of South-Eastern Norway), Flaminia Giacomini (Rome Tor Vergata), Philipp Höhn (OIST Okinawa), Esteban Castro Ruiz (IQOQI-Vienna)
Zoom link in the email.

WG1 - Online Meeting 9
2026-01-13 16:00 - 17:00
The link for the meeting will be sent by email, the program will be announced in the beginning of January after the new years break.
Everyone interested is invited to join the meeting!

Astrophysical processes in Lorentz invariance violation studies: modeling and analysis
2026-02-04 08:00 - 2026-02-06 17:00 | LAPP, Annecy, France
The workshop “Astrophysical processes in Lorentz invariance violation studies: modelling and analysis” aims at developing methodologies to improve the modelling of the astrophysical sources that emit high-energy signals that can be used in quantum gravity searches. Understanding the physics of the source is crucial, since currently this is the main source of uncertainty in tests of quantum-gravity induced propagation anomalies. This workshop will be crucial in involving astrophysicists not working on quantum gravity who are however expert in source modelling.

WG1 - Online Meeting 10
2026-02-10 16:00 - 17:00
The main topic of tomorrows meeting will be “QG approaches vs QG-inspired phenomenology: how far can we get?” moderated by Alessia.
The meeting will take place via BigBlueButton, with the login details sent in email.
Anyone interested is invited to join the meeting!

BridgeQG WG2 monthly online meeting
2026-02-26 15:00 - 16:00
Francesco Salamida will give a talk on systematic effects in Lorentz Invariance Violation (LIV) studies of ultra-high-energy cosmic rays
(UHECRs).
The zoom link can be found in the email announcement.

BridgeQG WG1 - Online Meeting 10
2026-03-10 16:00 - 17:00
Christian Pfeifer will chair a discussion on “Different levels of (local) Lorentz invariance – What do we exactly mean when we say a theory is (local) Lorentz invariant?”
Link for the meeting in the email with the announcement.

BridgeQG online seminar for high schools and teachers
2026-03-24 11:00 - 12:00
Curious about the secrets of space, time, and gravity? Join us for the BridgeQG online seminar on Tuesday, March 24, 2026 at 11:00 CET! High school students and teachers worldwide are invited to explore the mysteries of the universe with leading researchers in quantum gravity. For more information:
https://web.infn.it/Brid…/2025/07/14/bridgeqghigh-schools/
Register here.

Observers and causality in Quantum Gravity
2026-04-21 08:00 - 2026-04-24 17:00 | Bratislava, Bratislava, Slovakia (Slovak Republic)
We are pleased to announce that the COST Actions RQI and BridgeQG are jointly organizing the conference “Observers and causality in quantum gravity” in Bratislava, Slovakia, which is going to happen on 21st – 24th April 2026.
http://quantum.physics.sk/ocqg2026
This conference aims to bring together disparate communities in quantum gravity and quantum information to discuss common foundational concepts, which are defined and employed in different ways across fields. Central topics will include the notions of observers and causality, but the scope extends to related ideas such as measurements, quantum reference frames, quantum groups, and more.
We will address questions such as:
– What structures are required to define observers in quantum gravity?
– What is the relation among the notions of observers, observables, and measurements?
– Which features of causal structure are genuinely new in quantum gravity compared to classical spacetime?
– Which other fundamental concepts should be examined to help build a shared conceptual language?
Confirmed invited speakers:
Charis Anastopoulos (U. of Patras)
Časlav Brukner (IQOQI Vienna)
Esteban Castro-Ruiz (IQOQI Vienna)
Kristina Giesel (Erlangen – Nuremberg U.)
Giulia Gubitosi (U. Napoli Federico II)
Eleni-Alexandra Kontou (King’s College London)
David Kubiznak (Charles U.)
Fedele Lizzi (U. Napoli Federico II and INFN)
Daniele Oriti (U. Complutense de Madrid)
T. Rick Perche (Nordita and Stockholm U.)
Kasia Rejner (U. of York)
Renato Renner (ETH Zurich)
V. Vilasini (U. of Grenoble Alpes)
Nelson Yokomizo (U. Federal de Minas Gerais)
Ying Zhao (MIT) [online]
Programme Committee:
Natália Salomé Móller (Slovak Academy of Sciences – SAV)
Lin-Qing Chen (IQOQI Vienna)
Thomas Galley (IQOQI Vienna)
Martin Krššák (Comenius U. in Bratislava)
Fabio Costa (Nordita and Stockholm U.)
Giulia Gubitosi (U. Napoli Federico II)
Charis Anastopoulous (U. of Patras)
Organizing committee:
Natália Salomé Móller (SAV)
Saadat Salman Shariff (SAV)
Radka Hovorkova (SAV)
Martin Krššák (Comenius U. in Bratislava)
Mário Ziman (SAV)
Submissions for contributed talks and posters are open now!
You can subscribe through this link:
https://docs.google.com/forms/d/e/1FAIpQLSd4vZKfeT7kSaftB3Y0ic5Kzd_xpxDFti66CWu0r-ofzT2v-w/viewform?usp=dialog
Looking forward to seeing you in Bratislava!
With kind regards,
Natália
On behalf of the organizing committee.

WG2 monthly meeting
2026-04-30 15:00 - 16:00
During the meeting, Dr. Sadashiv Sahoo (Indian Institute of Technology Bombay) will give a seminar on searches for Lorentz Invariance Violation
with the INO-CAL experiment, including future prospects and a discussion on the systematics impacting the analysis.
Zoom link will be sent by email.

WG1 - Online Meeting 12
2026-05-12 16:00 - 17:00
Ben Koch will chair a discussion on “What Can We Expect to Learn from Black Holes in the Context of Quantum Gravity?”
Abstract:
I will provide a brief overview of our current understanding of the classical and semiclassical description of black holes.
In the context of quantum gravity, several important questions arise that we hope to discuss:
Which of these features will survive in a full quantum-gravity framework?
Which open problems might be resolved by such a framework?
Can black holes point the way toward a fundamental theory of quantum gravity?
What signatures, if any, could eventually become accessible to observation or experiment?
Meeting link will be sent by email.

WG3 Focused discussion III: Observers in Quantum Spacetime
2026-05-27 15:00 - 16:00 | online
Dear WG 3 members,

We are delighted to announce the third session of our focused discussion series. This time, we continue a theme from the recent Bratislava workshop, with panellists bringing complementary perspectives.

Questions: Do we need a theory of observers to formulate quantum spacetime? If not, what are the reasons? If so, what minimal structures should such a model of observers possess?

Panelists: Renato Renner (ETH), Markus Müller (IQOQI-Vienna), Daniel Harlow (MIT)

Time: May 27 Wednesday 3 pm – 5 pm CET

The meeting link will be sent by email

WG2 monthly meeting
2026-05-28 15:00 - 16:00 | online
During the meeting, Dr. Julian Sitarek (the University of Lodz) will give a seminar on “Systematic effects in gamma-ray LIV studies with source modelling”.
Zoom link will be sent by email.

Training school: Quantum and classical gravity in low-energy quantum systems
2026-06-22 09:00 - 2026-06-26 13:00 | Faculty of Physics University of Belgrade, Belgrade, Serbia
The goal of this physics school is to offer master and Ph.D. students, a coherent introduction to the subject of quantum gravity in low energy quantum systems from both theoretical and experimental perspectives. While the focus of the first training school was on the high-energy aspects (WG1, WG2) of the BridgeQG network, the focus of this training school will be on the low-energy aspects (WG3, WG4). A third school will cover the combination of the two branches (WG5). The school consists of four main lectures, which are accompanied by hands on exercise classes. In addition there will be an introductory talk on Quantum gravity phenomenology, an evening talk and a concluding talk.
For more information, see the Indico page of the event here.

BridgeQG 2026 - Second COST Action CA23130 Annual Conference
2026-07-06 08:00 - 2026-07-09 17:00 | Varna, Varna, Bulgaria

Bridging low- energy high precision experiments with theory: a roadmap towards measurable signatures of quantum gravity
2026-09-16 08:00 - 2026-09-18 17:00 | Gran Sasso, L'Aquila, Italy
The workshop “Bridging low-energy high precision experiments with theory: a roadmap towards measurable signatures of quantum gravity” aims at connecting theoretical research on low-energy quantum gravity effects with observational frameworks. It will involve mostly Action participants who are members of WG3 and WG4. We foresee to have short presentation by attendants and ample time for discussion in order to facilitate progress. The workshop will be held in Gran Sasso facilities, where experiments on tests of low-energy quantum gravity effects are currently being designed.
