Category: Conferences

MAD Workshop is an excellent opportunity to connect with collegues involved in the development of advanced materials for gravitational wave detectors as well as with researchers from crystal growth community and industry who share a deep interest in the topic. Together we will discuss recent achievements and challenges in material research and outline prospects for future cooperation. We are confident that face-to-face workshops with a lot of space for personal interaction and individual meetings will contribute to achieving our common goals.

Workshop Website

The workshop will focus on compact object binaries ranging from stellar mass objects to supermassive black holes. The workshop aims to discuss our current understanding of gravitational-wave sources based on the previous gravitational-wave and electromagnetic observations and what we will be able to learn from future observations. Topics to be considered at the workshop include:

Dynamical channel of binary black hole formation
Binary stellar evolution/population
Binary black holes in AGNs
Intermediate - supermassive binary black holes
Electromagnetic signatures of compact binaries
Gravitational-wave data analysis

The workshop is hosted by the Research Center for the Early Universe at University of Tokyo.

Participation and Program

All participants are requested to register by filling out the “Registration” form via the menu on the left of this page. Participants interested in contributing with a talk must also submit an abstract by filling out the “Title of talk” and “Abstract”,  in the registration form. The workshop can accept a limited number  of participants due to the capacity of the room.  In order to receive full consideration, all information must be received by September 15th, 2026. The acceptance of the workshop will be given by September 25th, 2026. 

We plan to focus on invited and contribution talks in the first week. In the second week, we will have a  small number of  talks and  a large fraction of time will be devoted to open discussion. 

Venue

The workshop will take place at Science building No. 1 in the Hongo campus of University of Tokyo.  

Registration fee

The registration fee is 5000 JPY (~33 USD, 30 EUR).  The cost of workshop dinner is  7,000 JPY. The payment method will be annouced later to the accepted participants.

Workshop Dinners

To be determined.

Accommodation

We recommend any business hotel in the Hongo or Ueno area. For example, APA Hotel Keisei Ueno-Ekimae is a business hotel at a walkable distance from UTokyo, just across the Ueno park. Other APA hotels are also nearby (Ueno Eki Minami, Ueno Ekimae, Shin Okachimachi Ekimae). There are many other hotels in the Ueno area.

If you want to stay farther away from the university, commuting by metro is also an easy option. The Hongo campus is well connected to the Marunouchi and Oedo lines (Hongo Sanchome station), the Namboku line (Todaimae st.) and the Chiyoda line (Nezu st.).

For using local transportation, we recommend buying a rechargeable Pasmo (or Suica) card.

Invited Speakers

• Pau Amaro Seoane (Polytechnic University of Valencia)*
• Clement Bonnerot (U of Birmingham)
• Alexander Dittmann (IAS)
• Kohei Inayoshi (KIAA)
• Maximiliano Isi (Columbia)
• Dong Lai (TDLI)
• Wenbin Lu (UCB)
• Andrew MacFadyen (NYU)
• Lucio Mayer (UZH)
• Ehud Nakar (Tel Aviv)
• Smadar Naoz (UCLA)
• Matt Nicholl (Queen’s University Belfast)
• Samaya Nissanke (DESY)
• Re’em Sari (Hebrew U)
• Ataru Tanikawa (Fukui Prefectural U)
• and more (* to be confirmed)

Organizers

• Kenta Hotokezaka, University of Tokyo
• Daniel D’Orazio, Space Telescope Science Institute
• Martin Pessah, Niels Bohr Institute
• Johan Samsing, Niels Bohr Institute
• Soichiro Morisaki, University of Tokyo
• Masaki Ando, University of Tokyo
• Tomoya Kinugawa, Shinshu University

Contact

• Workshop LOC < resceu-nbia-2026-group at g.ecc.u-tokyo.ac.jp >

We gratefully acknowledge the support by the Research Center for the Early Universe at University of Tokyo, the JST FOREST Program (JPMJFR2136) and the JSPS Grant-in-Aid for Scientific Research (23H01169, 23H04900).

Workshop Website

How binary black holes and neutron stars form and merge is the central question in gravitational-wave astrophysics. A decade after the first direct detection of a binary black hole merger, it remains unclear which gravitational-wave events probe the evolution of isolated massive binary stars, the dynamics of dense environments like star clusters, and active galactic nuclei, or more exotic pathways. One of the main hurdles has been the low-number statistics that prevented statistically robust identification of sub-populations within the observed population of gravitational-waves.

With the full O4 catalogue expected by the end of 2026, the sample is set to grow to several hundred events, ushering gravitational-wave astronomy into a new era of precision population inference. For the first time, this enables robust multi-parameter analyses (masses, spins, eccentricities, and their correlations) which are crucial for breaking the degeneracies that currently prevent us from deciphering the astrophysical origin of compact-object mergers.

The recent O4a and O4b releases have already prompted several interesting (and sometimes competing) claims about the origins of binary black hole subpopulations, including evidence for hierarchical mergers, features associated with the supernova-remnant mass function, and imprints of isolated binary and triple-star evolution. Many of these results remain only partially supported. In parallel, EM observations from (like the Gaia DR4 release) are substantially expanding the sample of dormant compact objects in binaries with luminous companions, providing essential context for interpreting gravitational-wave events.

Taking place just a few weeks after the planned full O4 data release, the workshop will be a timely opportunity to discuss the wealth of new results from the enlarged gravitational-wave catalogue. It will bring together researchers working on astrophysical theory and modelling, numerical relativity, and gravitational-wave data analysis to explore what are the astrophysical lessons that can be robustly drawn from O4.

The workshop will have a very heavy focus on discussions and interactions to promote problem solving structured around three themes:

• Astrophysical modelling: merger signatures expected from different formation channels
• Data analysis: which features in the data are robust
• Falsification: how the new data constrain and refine astrophysical models

Registration deadline: 8 November 2026

The number of participants is limited. We will confirm participation shortly after registration closes.

Organizers

Jakob Stegmann (MPA), Lieke van Son (Radboud University), Davide Gerosa (Milano-Bicocca), Samaya Nissanke (DESY/DZA), and Salvatore Vitale (MIT).

Workshop Website