I can say with full confidence I’m the happiest person on this planet right now. Seeing the Roman Space Telescope being assembled — and knowing it’ll be in orbit next year — just makes it unreal.

Hello again, DC 🤗

It’s a wrap! @nasaromantelescope.bsky.social NASA Roman HLIS Cosmology Project Infrastructure Team face to face meeting Thank you to Bhuv, Mike and the rest of UPenn folk for hosting us 🙏

Hey all I need help from my physics peeps (and beyond) Do you (or if you are a PI: your students/postdocs) use numerical derivatives in your research? Especially in inference (but also in general) Apparently I can’t do a poll here so pls respond and share

The only acceptable way to start the Leiden research visit is to have coffee with Dr Evil Villain (in our secret Narnia caffe) @ivovanvulpen.bsky.social (For those of you who don’t know, Ivo is responsible for the amazing wall formulas in Leiden; see photo 2 where Matthijs and I are kissing)

Happy to be back in one of the loveliest places on this planet 🇳🇱🚲🌷🧀🌊

Interested in a fully funded PhD place in Experimental Particle Physics in Edinburgh? We have fully funded studentships, including a specific scholarship for students from a Black heritage (including mixed Black background). More info: inspirehep.net/jobs/3080808

Statistical properties of the gravitational force through ordering statistics. Constantin Payerne et. al. https://arxiv.org/abs/2201.08478

One of the perks of academia — you have awesome colleagues all over the world so dinners in great company are always guaranteed

Lovely day at the Paris observatory with old Twitter friends! All Paris talks delivered!

When two stats nerds from way back randomly find themselves in Paris at the same time — talk about serendipity!!!! @knut.dundasmora.no 😍 It was beyond lovely to spend an afternoon in Paris with you

Bonjour!

Happy Halloween from me and my buggy code

A little treat for myself: two adorable mini Kurt Geiger bags ✨ My first one was a Heathrow purchase two years ago — guess it was the start of a collection 👀

helloooooooooooooooooooo wanna learn about telescopes and how to navigate the night sky? funny you mention that, because we're doing another starhopping and telescopes night with @spacecentreyvr.bsky.social on november 12!! get your f r e e tickets here: 🔗 www.eventbrite.ca/e/rasc-vanco... 🔭🌌

clicked to generate a random xkcd and it could have not be more appropriate considering my current situation xkcd.com/2797/

🤬 why does everything pass locally on macOS but CI (Linux) decides my cubic’s 3rd derivative is 24.0000001999 instead of 24?! Apparently OpenBLAS and Apple’s Accelerate don’t round the same way 🤦‍♀️ IT IS UNIXXXXXXXX Numerical analysis: 1, sanity: 0 (Managed to fix, still angry)

6 °C in Durham this morning 🌿 Early woods + chilly air = time to grab a shovel! Cleared out a bunch of sweet gum trees — perfect, since we’re expanding the food gardens AND the lemurs get a feast 🍃 A wonderful morning at the Duke Lemur Center with my garden crew 🦋

I also spent some hours this weekend giving my @github profile a glow-up — it’s orange 🟠 and has parrots 🦜 check it out: github.com/nikosarcevic

spent an embarrassingly long time making these plots (wanted to procrastinate) holy pagan gods, @matplotlib has been on fireeeee 🔥 the past few days i think they’re correct … but for now i’m just gonna enjoy looking at them because they pretty 🤩 thanks to @matthijs.vanderwild.com for helping 😍

The sky is particularly beautiful here in NC So is the Moon 🌕🤩

In response to increasing activity, we wish to add more members to our Editorial Board. We're looking for expertise in any area of astrophysics, but people working in instrumentation or stellar astrophysics are particular welcome. Please contact us here if you want to volunteer! astro.theoj.org

New paper out, baby We build & validate six intrinsic alignment models infused directly into weak lensing simulations, enabling robust inference beyond 2pt stats. I led the full validation with MCMC chains—took years to get here! Excited this is FINALLY out 🎉 arxiv.org/abs/2509.25166

Yesterday I submitted 6 prs that were perfect not only to review but also to merge and rebase with no conflicts. I was proud. Today I do one pr on top of two PRs and suddenly there is a merge conflict cherry pick hell I’m going to go listen to Maynard screams on YouTube

Dark Energy Survey Year 6 Results: improved mitigation of spatially varying observational systematics with masking. M. Rodríguez-Monroy et. al. https://arxiv.org/abs/2509.07943

I am so good at multitasking between bash WhatsApp and slack

Oh you bought another book? Did you finish the life sentence yet? Yes. No. Also, blame it on @telescoper.bsky.social for posting about this book yesterday.

In the past 2 weeks I have reviewed 5 papers — 3 for journals and two of the ones I’m involved with Also countless PR reviews back and forth I don’t have eyes any more 👀👀👀👀🔥🔥🔥🔥🔥🔥🔥

I pay for all the subscriptions both in the UK and the US Matthijs texted me he ordered some household essentials on Amazon this morning The household essentials: 🤣🤣🤣🤣🤣🤣😅😅😅

Presented my work recently. A colleague directed questions about MY plot to the senior male professor. I had to step in, almost going full Slav on him: “Why are you asking him? This is my work.” It’s not just rude — it’s a pattern where women’s work in science is undermined.

Heavy lifting at the Duke Lemur Center this morning! 😌

Here are more photos (Šarčević et al., 🤩) taken during the LSST DESC and echoIA workshops I had the pleasure of organizing here at @DukePhysics

Hey, Astro peeps, help needed Are there any developments (preferably codes) in the Astro world for the k+e corrections? Ideally I’d need a z, photo band and gal type dependent k+e corrs (higher z not just local universe) Does that exist in 2025 😬🫠

Taken by me at exactly 5:37 am in Durham NC looking east No clue what it is but deffo was interesting

First morning volunteering at the Duke Lemur Center 🌱 Did some gardening, picked veggies for the lemurs, met cool people, weeded a bunch. It was fun — and we found a bunch of these small guys 🐍 Bliss 😌😌😌

Had the pleasure of spending this afternoon talking about cosmology, my journey here to Duke, and more with the wonderful hosts of the KnowmadsPodcast. 🎙️ Follow them to catch their episodes—my recording will be up soon and I’ll share it here! TY for having me!

Recorded an episode of The Knowmads Podcast with Eve Vavagiakis @evevavagiakis.bsky.social , Experimental Cosmologist from Duke University. It was one of the most refreshing conversations ever! We (@bhavaytyagi.bsky.social and I) can’t wait to share it with y’all.

Just unpacked a stunning shipment from @pennmuseum.bsky.social : • Canopic jar set (made in Egypt, super heavy!) • Mayan carved bone • Jaina figure Huge thanks to the gift shop staff for the careful packing—it all arrived in perfect condition. I love this so much! 🖤

The bane of my existence: people using @github.com as a glorified googledrive. I swear I waste my life cleaning up repos—it’s unbearable please people, stop no mas

A bday stroll thru the ever amazing Sarah Duke Gardens 😌

It’s my birthday today My wish for the future: less hatred, violence, and glorification of ignorance — and more compassion, love, curiosity about the universe, and the joy of working together to build a better world. 🌎🌻🌲🐈🦔🔭🦠🧫🔬🎨🤖🎼🎸📚📖🏛️🌌❤️

One of the main reasons (apart from being an absolute amazing center of history/art/science/culture) why I think Philly is amazing: it is just so walkable 😍

Nothing like a spicy Japanese ramen after 10 hours traveling 1/

Hey @seanmcarroll.bsky.social We’re at your old stomping ground

Vacation time! 🚂 Destination: 🇺🇸 | 🔔 | 🥊🏃 | 🧀🥩

So this guy MOVED from where he was and then threw the kernels at me while I was standing in the forest having a phone call 😅 Literally moved to be above me, little rascal Squirrels are insane (still love them

Academic family trees are awesome

When you book a hotel 15 min from the White House (by foot) for under $600 for 4 nights 🇺🇸

I once* applied so many cuts in the name of “precision” that I only realized I had one data point left when I saw the fit. Absolute clown. *today

Niko: I’m gonna finish my part of the project this week. Life: here’s a bit of dependency hell for Monday