Simon Birrer

Wow, big congrats to TDCOSMO for their `Milestone’ paper: arxiv.org/abs/2506.03023 . They analyze 8 strongly lensed quasars and find Hubble constant of 72+-3 km/s/Mpc with supernova prior on Omega_M, and H0=73+-3 with DESI BAO prior. This was one of the two local H0 studies from JWST I was most excited to see this year because the teams and tools are independent of SH0ES (other was the TRGB-SBF Project, got 73.8+-2.4). This was an amazing 6 year (!!) journey by TDCOSMO to get here..Story time..

Excited to share the latest work on measuring the Hubble constant by the TDCOSMO collaboration: arxiv.org/abs/2506.03023 This work was five years in the making by many excellent people

IT'S HAPPENING: Strongest EVER constraints on the free-streaming length of dark matter from a combination of the first 9 lenses in our @NASAWebb program and 5 previously measured lenses. This work was led by @ucmerced postdoc @RyanEKeeley arxiv.org/abs/2405.01620

So excited about this paper! arxiv.org/abs/2403.03253 It's an idea we've had for years but implementing was very challenging. The brilliant @MrGilmanDa led this, with major innovations that will revolutionize our dark matter measurements. With @maverick_sh_oh and @sibirrer

Calling all citizen scientists! DES is looking for YOUR help to look at our images and find gravitational lenses! Anyone can participate in this limited-time scientific project, hosted by @the_zooniverse and @SpaceWarps . Start now at: zooniverse.org/projects/apraj…

Announcing the first paper from our JWST lensed quasar dark matter survey. TLDR: We are optimistic we will be able to to use the full survey to confirm the existence of completely dark, dark matter halos if they exist. arxiv.org/abs/2309.10101

A new study published in @ScienceMagazine by researchers including Dept. of Physics & Astronomy Assistant Professor @sibirrer & Associate Professor Anja von der Linden uses supernova images to measure the expansion rate of the Universe. @sbuartssciences news.stonybrook.edu/newsroom/new-s…

Congratulations Victoria Grove, Grants Manager for the Department of Physics and Astronomy, on receiving a College of Arts and Sciences Staff Excellence award! #stonybrookuniversity #staff #excellence

omg @Stanford already starting with blatant union-busting rhetoric: "Stanford’s relationship with our graduate students is, first and foremost, an educational one." babe no, grad students are *workers* whose labor props up the university, come on we've been through this

What is the first thing you would do if you had a living wage? SBU and other (grad) workers reply here to answer!

Bonus: We use raytracing in Lenstronomy to enhance the lensing scales of large-scale simulations. Starting with convergence computed on a coarse ~1' grid, we introduce finer fluctuations on galaxy lensing scales of ~1" to generate our training set. github.com/lenstronomy/le…

Paper alert🚨 Proteins are my new dark energy, but my latest paper employs hierarchical Bayesian inference, importance sampling, deep sets – all methods close to my heart! 🧵arxiv.org/abs/2211.07807

We are super excited to announce a mini lecture series on #JWST early science! How is this legendary telescope changing our understanding of first galaxies, cosmology, and exoplanets? Join us on Oct. 25 for the first talk in the series. 🌌 More info: goto.stanford.edu/jwst-galaxies