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GRAPPA Centre @grappainstitute.bsky.social · 01/08/2025

Moreover, thanks to simulation reuse enabled by SBI, they could perform the combined analysis using *zero* calls to a Boltzmann solver

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GRAPPA Centre @grappainstitute.bsky.social · 01/08/2025

To illustrate their method, they combine the full Planck CMB likelihoods with a 3x2pt simulator for a Stage IV galaxy survey (e.g. Euclid), and test evolving dark energy. They find that future 3x2pt data *alone* could detect dynamical dark energy preferred by DESI at the *5sigma* level

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GRAPPA Centre @grappainstitute.bsky.social · 01/08/2025

Looking for a summer read? Check out this new GRAPPA paper! arxiv.org/abs/2507.22990 The authors introduce a simple method to construct an effective simulator for *any* explicit likelihood, using samples from a previous MCMC

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GRAPPA Centre @grappainstitute.bsky.social · 21/05/2025

Huge congratulations to Dr. Uddipta Bhardwaj, who successfully defended his PhD thesis "Sequentially learning Gravity" on the 19th of May 2025 🥳

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GRAPPA Centre @grappainstitute.bsky.social · 16/05/2025

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

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GRAPPA Centre @grappainstitute.bsky.social · 16/05/2025

New GRAPPA paper! arxiv.org/abs/2505.097... The authors (Rodrigo Vicente, Theophanes Karydas, @gfbertone.bsky.social) introduce a relativistic framework to model environmental effects on extreme mass-ratio inspirals (EMRIs) in collisionless media

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GRAPPA Centre @grappainstitute.bsky.social · 12/05/2025

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

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GRAPPA Centre @grappainstitute.bsky.social · 10/03/2025

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"

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GRAPPA Centre @grappainstitute.bsky.social · 28/01/2025

Celebrating the start of the year with our fantastic GRAPPA members 🥂🥳🎉

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GRAPPA Centre @grappainstitute.bsky.social · 08/12/2024

Inspiring and wonderful article about former GRAPPA PhD student Gimmy Tomaselli on dutch newspaper NRC. Congratulations! www.pressreader.com/netherlands/...

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GRAPPA Centre @grappainstitute.bsky.social · 10/11/2024

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! arxiv.org/abs/2410.15808 Led by GRAPPA PhD Oleg Savchenko

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GRAPPA Centre @grappainstitute.bsky.social · 25/03/2024

As an application to non-gaussian posteriors, the authors also test a model of 2-body decaying dark matter, finding that Stage IV surveys can improve current bounds by up to 1 order of magnitude!

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GRAPPA Centre @grappainstitute.bsky.social · 25/03/2024

They are able to recover the posterior distribution of all parameters with a speedup factor of ~40-60 compared to MCMC!

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GRAPPA Centre @grappainstitute.bsky.social · 25/03/2024

New GRAPPA paper! arxiv.org/abs/2403.14750 The authors show the first application of Marginal Neural Ratio Estimation (MNRE) to accelerate parameter inference from upcoming Stage IV photometric surveys (like Euclid or LSST)

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GRAPPA Centre @grappainstitute.bsky.social · 15/01/2024

Celebrating and sharing the New Year with our fantastic GRAPPA members 🎉🎉🎉

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GRAPPA Centre @grappainstitute.bsky.social · 04/12/2023

Check out the new poetic-philosophical documentary "Neutrino", with the participation of GRAPPA member Patrick Decowski! More info at neutrinofilm.nl

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