Sun Woo Kim

Sun Woo Kim

@sunwoopkim.bsky.social

Theoretical physicist. Student researcher at Google Quantum AI and PhD candidate at King's College London. Same handle on 🐦 and 🐘. Personal website: https://sunwoo-kim.github.io

624 followers213 following217 posts

Sun Woo Kim reposted

Replying to @lauriewired.bsky.social

Interesting thought experiment: if you had noise-cancelling headphones that had 'antennas', such that you place microphones further away from your head (to get early warning of sounds), how long would the antennas have to be such that you can cancel out gunshots?

features: (a) you can add to the end of the url to specify cities, e.g. #newyork,london,paris. (b) responsive design so it should work on your phone too. (c) when you scroll the city names are persistent. (d) click on a time to highlight

Sun Woo Kim reposted

We used this to show exact KPZ scaling, first time in a deterministic chaotic system with one conserved quantity! This setup gives a controlled environment to test hydrodynamical theories; we expect it to be useful in the future. (2/3)

With Max McGinley, we came up with a very general and mathematically rigorous technique to bound recovery thresholds and diagonose mixed-state topological order. Excited to have it out, let us know what you think! (2/2)

Sun Woo Kim reposted

'Solvable' circuits, such as dual-unitaries, have gained attention recently as a paradigm of tractable many-body dynamics. With Friedrich Hübner, we came up with necessary and sufficient conditions for any (1+1)D circuit to be 'influence-solvable'. Happy to hear thoughts! arxiv.org/abs/2606.12538

arxiv.orgInfluence-solvability: a systematic theory of $(1+1)D$ solvability and its application to brickwork circuits`Solvable' circuits, such as dual unitaries and its generalisations, have arisen as paradigmatic examples of tractable chaotic non-equilibrium dynamics, both in classical and quantum systems. However,...

'Solvable' circuits, such as dual-unitaries, have gained attention recently as a paradigm of tractable many-body dynamics. With Friedrich Hübner, we came up with necessary and sufficient conditions for any (1+1)D circuit to be 'influence-solvable'. Happy to hear thoughts! arxiv.org/abs/2606.12538

arxiv.orgInfluence-solvability: a systematic theory of $(1+1)D$ solvability and its application to brickwork circuits`Solvable' circuits, such as dual unitaries and its generalisations, have arisen as paradigmatic examples of tractable chaotic non-equilibrium dynamics, both in classical and quantum systems. However,...

Sun Woo Kim reposted

ArXiV has a new LLM policy (Screenshots with alt text so you don’t have to click through to the other place and see all the stupid responses)

Has anyone else noticed that Norm MacDonald's moth joke sounds just like Crime and Punishment? Only started reading the latter recently and can't stop laughing when reading it, though it's supposed to be serious I assume...

Sun Woo Kim reposted

coming from windows? life pro tip! create a puzzling '3D Objects' folder on your OS of choice to make it feel more familiar

Sun Woo Kim reposted

Replying to @sunwoopkim.bsky.social

Actually, I think there are infinite, but are all variations of that 7 hex case with a fully connected middle tile. Removing that, not convinced a non-trivial solution configuration exists (eg. swapping a straight line 180 degrees). Would love to be proven wrong! Here's a 9 hex case I found.

For some reason I thought the left was a giant apple

Katie Mack@astrokatie.com

Whoa 🤯 The Moon, in full eclipse, with the #Artemis II Orion spacecraft. Part of the Moon and spacecraft are lit by Earthshine, and both Saturn and Mars are visible to the lower right. Incredible. Details: images.nasa.gov/details/art0...

Sun Woo Kim reposted

Replying to @austen.uk

From a pen & paper theorist point of view, I find it much harder to fall into the trap described here, since I find that it *is* the point to understand every detail of the proof (as you say). In contrast, for coding, often I just want a function without understanding every detail and I start vibing

Sun Woo Kim reposted

UK greenhouse gas emissions are now down 54% since 1990. They fell 2% last year. It's something the country doesn't boast about enough. Yes, some of it is switch from industry to services. But the biggest reductions are from changes to electricity supply. 👇 www.gov.uk/government/s...

Sun Woo Kim reposted

If you have agents who are perfect Bayesians, surely they have a prior and posterior modelling the other agents. But then they have to model that they have a prior and posterior etc... how does one stop the infinite recursion?

If you have agents who are perfect Bayesians, surely they have a prior and posterior modelling the other agents. But then they have to model that they have a prior and posterior etc... how does one stop the infinite recursion?

Sun Woo Kim reposted

Replying to @johncarlosbaez.bsky.social

Hot take: distributions with infinite variance don't really exist in real life. Everything has a cutoff due to system size. Of course, if the system size grows, then the cutoff grows. So in my opinion distributions with infinite variance are really describing a limit.

Sun Woo Kim reposted

In somebody else's words:

Sam Power@spmontecarlo.bsky.social

In the end, speaking in broad terms, to me, there's a lot of appeal in estimating with optimism, and then representing uncertainty with a bit more conservatism. The rigidity of the latter enables the flexibility of the former, at least if you can 'do it properly' by some measure.

Is measuring syndromes then using a decoder to infer the most likely error the best thing to do when trying to do quantum error correction? I prove cases where it is, where it isn't, and how to find the optimal threshold. Happy to get this out: let me know what you think! scirate.com/arxiv/2603.0...

scirate.comOptimal recovery for quantum error correctionThe calculation of the error threshold of quantum error correcting codes typically proceeds as follows. First, syndromes are measured. Then, a decoder infers the error chain and the corresponding corr...

Yeah but really just two sizes right

Quanta Magazine@quantamagazine.org

By showing that infinities can come in different sizes, Cantor called into question what mathematicians thought they knew. This led to new areas of study, and to a reckoning in the field — about what math was capable of, and what math even was.