iiinova — where your digital self keeps evolving

Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 02/09/2026

arXiv submission statistics for the quant-ph channel for the last 5 years, 2 years, 6 months.

Plot of the arXiv submissions to the quant-ph channels in the last 5 years.

Plot of the arXiv submissions to the quant-ph channels in the last 2 years.

Plot of the arXiv submissions to the quant-ph channels in the last 6 months.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 05/08/2026

"Integrated colorings are more widely referred to as unfriendly partitions in the literature, as first published in [1]. Nonetheless, we adopt the more inclusive language here." Like, what?

Excerpt from the paper https://arxiv.org/abs/2506.07192 about strange and problematic terminology in graph theory.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 23/07/2026

Whenever a stranger enters the apartment (such as the locksmith right now), they go to their safe space to assess the situation 😅 (we've only had them for three months, they're 1yr old, but making huge progress with coming out of their shells)

Cumin and Paprika being sceptical of strangers in the apartment.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 04/07/2026

This is how we're hunting. They're lucky they don't need to hunt their own food.

Cumin and Paprika, our two black cats, "hunting" their favorite bird feather toy.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 28/06/2026

No Selfie, no Math today, but Cumin and Paprika scream "lazy Sunday" in this picture 😹

Our two black cats Cumin and Paprika napping on the cat tree platform.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 28/05/2026

Sent this to my group. The perpetrators shall remain nameless.

$Geordi La Forge meme advertising to use \coloneqq, \|X\| and f\colon X \to Y in LaTeX instead of :=, ||X||, f: X\to Y.$

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 17/05/2026

I think arXiv makes that fairly easy actually, the DOI and the export Bib data function (that includes the fields in my skeet above) are right there on every arXiv posting page!

Screenshot of an arXiv posting highlighting the DOI link and the "Export BibTex citation" button.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 07/05/2026

UIUC Canvas has been hacked, as have many more universities. The hackers clearly know that finals are ongoing to maximize damage with this.

Message showing that the UIUC Canvas space was hacked by some group called "Shinyhunters".

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 30/04/2026

Yes Google I know, because I can't for the life of me remember the 1000 identities involving binomial coefficients.

Google search result for the wiki page "Binomial coeffcient", with a badge saying "You visit often".

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 14/04/2026

A little task to get your brain going today: Prove the statement in the picture!

$A mathematical statement involving operator inequalities and tensor products. Statement in LaTeX: Let $X,Y$ be operators on a finite-dimensional Hilbert space. If $0\leq X \leq Y$, then $X^{\otimes n} \leq Y^{\otimes n}$ for all $n\in\mathbb{N}$.$

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 04/09/2025

Sending good vibes! With a big cat from the St Louis Zoo just being a cat.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 15/08/2025

For the 6th season in a row I'm fielding my "Entanglement Wedges" team in Fantasy Premier League. To the best of my knowledge this term was coined in arxiv.org/abs/1704.05839. #FPL #FPLBluesky #FPLCommunity

My FPL team for Gameweek 1:

Sanchez - Virgil, Van de Ven, N. Williams - Dewsbury-Hall, Palmer, M. Salah, Rice, B. Fernandes - Watkins, João Pedro

Subs: Valdimarsson, Wan-Bissaka, Kalajdžić, Tuanzebe

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 16/07/2025

"Freie Wissenschaft ist ebenso selbstverständlich wie freies Atmen." - Lise Meitner Free science is as natural as breathing freely. Seen in a Munich subway station.

Sign in the Munich subway showing the quote from Lise Meitner given in the post.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 03/06/2025

I went to @powells.bsky.social in Portland, OR (great bookstore, check it out!) and secured a signed copy of @rhodesben.bsky.social's "After the Fall" 🤗

Signed copy of Ben Rhodes's "After the Fall - The rise of authoritarianism in the world we've made"

Autograph page and a bookmark from Powell's in Portland, OR

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 23/04/2025

Excerpt from Roger Howe's "Perspectives on Invariant theory: Schur duality, multiplicity-free actions and beyond". I will make sure to start next term's lecture on Schur-Weyl duality with "Now with the multilinear algebra nonsense out of the way, let's do some double commutant yoga!"

Excerpt from a paper by Roger Howe on invariant theory, mentioning "Weyl's proof of this theorem uses some general nonsense of multilinear algebra" and "the double commutant yoga yields the theorem".

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 13/04/2025

We finally have a copy of Quantum Steampunk, and signed by Nicole with a personal dedication 😍

A copy of the book Quantum Steampunk written by Nicole Yunger Halpern

A personal dedication from Nicole Yunger Halpern in a copy of her book on Quantum Steampunk

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 31/03/2025

I haven't written a textbook yet, but if I ever do I should try to have a red book cover theme

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 31/03/2025

Remember Mike and Ike? Well I have found another one.

Wilde chips next to Mark Wilde's textbook on Quantum Information Theory

Mike and Ike candy next to Michael Nielsen's and Isaac Chuang's textbook Quantum Computation and Quantum Information

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 18/03/2025

In quantum information theory you sometimes need to have an explicit form of the complementary channel of a quantum channel. Given a Kraus representation of the original channel, it's straightforward to write down a Kraus representation of the complementary channel via slicing arrays!

Visualization of the Kraus operators of a quantum channel and its complementary channel by slicing a 3-D array in different ways.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 17/03/2025

Continuing PSAs of potentially lesser known facts in QIT: spanning sets for the symmetric subspace! It is quite well-known that the set {|v>^{⊗n}: |v> ∈ H} spans the symmetric subspace Sym^n(H). But taking all vectors with components from a finite set A also spans Sym^n(H), provided |A|≥n+1!

Excerpt from John Watrous's book on Quantum Information Theory, showing Theorem 7.5 about spanning sets for the symmetric subspace. See https://cs.uwaterloo.ca/~watrous/TQI/

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 25/02/2025

hello darkness my old friend, I've come to talk with you again let's do this #QIP2025

About to board flight AA600 to Raleigh, NC to attend QIP2025.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 12/02/2025

"ChatGPT can make mistakes. Check important info." Glad to see that I still have a job.

Wrong example of three orthogonal vectors because ChatGPT thinks that -6 + 0 + 0 = 0.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 12/12/2024

(ok technically this was recorded and released in 2000 but I'm gonna play it anyways)

Die Fantastischen Vier - MTV Unplugged (2000)

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 12/12/2024

Post a PERFECT album from the 90's that is neither Nirvana nor Pearl Jam.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 09/12/2024

A group picture featuring Nilanjana Datta and all of her former and current PhD students, taken during the birthday symposium Mark Wilde and I organized for (and with) her in good ol' Cambridge this summer. I feel so lucky to have had Nilanjana as my PhD advisor!

Quantum information theorist Nilanjana Datta with all of her former and current PhD students.

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 26/11/2024

You need cooling Baby I'm not fooling I'm gonna send ya Back to schooling

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 22/11/2024

Michelle thought I'd be into this IPA and... I am 🤓. It's called Parity Error and brewed by #STL local brewery Alpha Brewing Company

Parity Error IPA by St Louis based Alpha Brewing Company

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Felix Leditzky 🏳️‍🌈🏳️‍⚧️ @felixleditzky.info · 17/11/2024

Reposting here from the other place: The 6 inequivalent SLOCC classes for three qubits from arxiv.org/abs/quant-ph... were already computed in an example on p.478 in the book "Discriminants, Resultants, and Multidimensional Determinants" written by Gelfand, Kapranov, and Zelevinsky in 1994 🤓

Three qubits can be entangled in two different ways.

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