Author Archives: Mateus Araújo

For mysterious reasons, some time ago I found myself reading SeDuMi’s manual. To my surprise, it claimed to support SDPs with complex numbers. More specifically, it could handle positive semidefiniteness constraints on complex Hermitian matrices, instead of only real symmetric … Continue reading →

I usually say the opposite to my students: that SDPs are the cheat codes of quantum information. That if you can formulate your problem as an SDP you’re in heaven: there will be an efficient algorithm for finding numerical solutions, … Continue reading →

I’m in a terrible mood. Maybe it’s just the relentless blackness of Austrian winter, but I do have rational reasons to be annoyed. First is the firehose of nonsense coming from the wormhole-in-a-quantum-computer people, that I wrote about in my … Continue reading →

Yesterday Quanta Magazine published an article written by Natalie Wolchover, Physicists Create a Wormhole Using a Quantum Computer. I’m shocked and disappointed. I thought Quanta Magazine was the most respectable source of science news, they have published several quality, in-depth … Continue reading →

If something is true for dimension 2, it doesn’t mean much. We know that 2 is very special. The set of valid quantum states is a sphere, we can have a basis of unitary and Hermitian matrices for the Hilbert … Continue reading →

It happens all the time. You make an experiment on nonlocality or steering, and you want to test whether the data you collected is compatible with hidden variables. You plug them into the computer and the answer is no, they … Continue reading →

Stuck at home with corona, I decided to try my hand at writing science fiction to pass the time. The result was not science fiction at all, but I think it’s still fun to read, so I’m posting it here. … Continue reading →

It’s the kind of commandment that would actually impress me if it were in the Bible, something obviously outside the knowledge of a primitive people living in the Middle East millennia ago. It’s quite lame to have a book that … Continue reading →

(thanks to Flavio Baccari for the photo) After more than two years of the world conspiring against me and Miguel, we finally managed to pull it off: the workshop in honour of Boris Tsirelson happened! In my opinion and of … Continue reading →

We often see experimental results reported with some “error bars”, such as saying that the mass of the Higgs boson is $125.10 \pm 0.14\, \mathrm{GeV/c^2}$. What do these error bars means, though? I asked some people what they thought it … Continue reading →