GRAPPA Centre

GRAPPA is a centre of excellence of the University of Amsterdam, focussing on Gravitation and Astroparticle Physics.

[GRAPPA Centre @GRAPPAinstitute]

Come join us at @GRAPPAinstitute!

Keep an eye on https://t.co/pp6Ol2hgDV for open PhD, Postdoc and Tenure-Track positions at @GRAPPAinstitute (as well as related positions at @uva_api).

[GRAPPA Centre @GRAPPAinstitute]

Huge congratulations to our new Dr. Uddipta Bhardwaj 🥳 we are most proud of you!

[Uddipta Bhardwaj @Uddi9]

On the 19th of May 2025, I successfully defended my thesis and was awarded my doctorate.

It's an honour to be surrounded by leaders across domains in physics.

Thank you to my advisors @samayanissanke @PhilippMoesta @C_Weniger for everything ❤️.
#academia #AcademicTwitter #PhD

[GRAPPA Centre @GRAPPAinstitute]

Applying it to the case of dark matter (DM) spikes around massive black holes (BHs), they show that a fully relativistic treatment is needed to accurately model the environmental dephasing of gravitational wave (GW) signals from EMRIs

[GRAPPA Centre @GRAPPAinstitute]

New GRAPPA paper! https://t.co/bMoFZMvRw0 The authors (Rodrigo Vicente, Theophanes Karydas, @gfbertone) introduce a relativistic framework to model environmental effects on extreme mass-ratio inspirals (EMRIs) in collisionless media

[GRAPPA Centre @GRAPPAinstitute]

Today we had a fantastic Colloquium by Dr. Malcolm Fairbairn (@KingsCollegeLon) to tell us about "Galaxies, Axions, Gravitational Waves, Black Holes and More Galaxies"

[GRAPPA Centre @GRAPPAinstitute]

It's a real pleasure to have Dr. Jonathan Gair (@mpi_grav) giving the GRAPPA Colloquium today, to tell us about "Opportunities and challenges in SBI for future gravitational wave detectors"

[GRAPPA Centre @GRAPPAinstitute]

He will use it to conduct six months of research at DESY, the German laboratory for high-energy physics in Berlin.

[GRAPPA Centre @GRAPPAinstitute]

Huge congrats to @JaccoVink for receiving the prestigious German Humboldt Prize for research!
https://t.co/UgZKXkSVSN

[GRAPPA Centre @GRAPPAinstitute]

Inspiring and wonderful article about former GRAPPA PhD student @gimmytomas in dutch newspaper NRC. Congratulations!
https://t.co/HpqxMFOHEt

[Samaya Nissanke (she/her) 🕊️❤️ @samayanissanke]

We had a busy & wonderful day ⁦@GRAPPAinstitute⁩ yesterday with 2 PhD defences! Huge congratulations to Dr Montel ⁦@AnauNoemi⁩ & Dr Tomaselli on their brilliant theses & defences. Such an honour to be on your defence committees. We are so proud of you & wish you the..

[GRAPPA Centre @GRAPPAinstitute]

It was fantastic having you the last 4 years at the Institute, you have been a key part of GRAPPA and we will certainly miss you! We wish you all the best for the future 🎉

[GRAPPA Centre @GRAPPAinstitute]

Huge congratulations to Dr. Anau Montel and Dr. Tomaselli for brilliant PhD defences today! 🥳🥳🥳

[Samaya Nissanke (she/her) 🕊️❤️ @samayanissanke]

Huge congratulations to Dr Tomaselli for a brilliant PhD defence and beautiful thesis, with cum laude & many congratulations to the proud supervisors Gianfranco Bertone @DD_Baumann @GRAPPAinstitute

[GRAPPA Centre @GRAPPAinstitute]

Congrats to all the authors!
Oleg Savchenko, Florian List, @GFAbellan, @AnauNoemi @C_Weniger

[GRAPPA Centre @GRAPPAinstitute]

The method relies on the assumption that the multi-million dimensional posterior of cosmic ICs can be described by a simple Gaussian, where the mean and covariance have been trained on the Quijote N-body simulations suite

[GRAPPA Centre @GRAPPAinstitute]

Owing to its simplicity, the method is significantly faster than other proposed algorithms (training only takes ~1h on a GPU, and sampling just ~3s for 1000 samples), while still being highly precise and interpretable

[GRAPPA Centre @GRAPPAinstitute]

Paper alert!
The authors introduce a fast and accurate method to reconstruct the cosmological initial conditions from present-day dark matter density fields, including uncertainty quantification!
https://t.co/QBSjpJaMbT
Led by GRAPPA PhD Oleg Savchenko

[GRAPPA Centre @GRAPPAinstitute]

This is the paper https://t.co/heTrcK0Zkg

[GRAPPA Centre @GRAPPAinstitute]

PBS Space Time has picked up a PRX paper by current and former GRAPPA members. Huge congrats to Dion Noordhuis, Anirudh Prabhu, Sam Witte and @C_Weniger for the fantastic piece of work!
https://t.co/mZBuAstF94

[Physical Review X @PhysRevX]

The work was done by Dion Noordhuis at @GRAPPAinstitute, Anirudh Prabhu (@Anirudh_14) at @Princeton, Christoph Wenigerat (@C_Weniger) the @GRAPPAinstitute, and Samuel J. Witte at @GRAPPAinstitute.

[Physical Review X @PhysRevX]

All active #NeutronStars should be surrounded by dense #AxionClouds if the axion has a mass in a specific range. This occurs because the polar caps of neutron stars produce axion clouds that are bound to the star and struggle to dissipate energy.

🔗 https://t.co/rg07BTA8xB