Mankei Tsang
@mankei-tsang.bsky.social
Associate Professor at the National University of Singapore. Quantum Metrology, Quantum Optics, Superresolution. https://blog.nus.edu.sg/mankei/
The Bhattacharyya distance is so much better in this case—gives both a tighter lower bound and an upper bound on the hypothesis-testing error, within a factor of two of the optimal Chernoff exponent, doesn't blow up with pure states in quantum, amenable to Riemannian treatment in info geometry.
November 5, 2025 at 12:11 PM
The Bhattacharyya distance is so much better in this case—gives both a tighter lower bound and an upper bound on the hypothesis-testing error, within a factor of two of the optimal Chernoff exponent, doesn't blow up with pure states in quantum, amenable to Riemannian treatment in info geometry.
They are very gracious in acknowledging our theory, but the real heroes are of course the experimentalists who have to make it work in practice. Let’s hope it’s the first of many—the quantum is the limit!
October 26, 2025 at 10:13 AM
They are very gracious in acknowledging our theory, but the real heroes are of course the experimentalists who have to make it work in practice. Let’s hope it’s the first of many—the quantum is the limit!
absolutely delighted that people found our idea useful.
October 25, 2025 at 6:42 PM
absolutely delighted that people found our idea useful.
Certainly a scientist of the highest calibre, but "greatest benefit to mankind"? Not sure about that.
October 7, 2025 at 9:22 AM
Certainly a scientist of the highest calibre, but "greatest benefit to mankind"? Not sure about that.
relative to what? V60?
September 18, 2025 at 10:40 AM
relative to what? V60?
Many have expressed interest in semiparametric theory but it seems to go over a lot of people's heads, so hope the notes help (although I'm hardly an expert on this). Quantum version follows naturally but not in the notes yet. P.S. I promise I'll come back to quantum and optics some day. (2/2)
August 28, 2025 at 3:33 PM
Many have expressed interest in semiparametric theory but it seems to go over a lot of people's heads, so hope the notes help (although I'm hardly an expert on this). Quantum version follows naturally but not in the notes yet. P.S. I promise I'll come back to quantum and optics some day. (2/2)
The long-term goal is to build a bridge from introductory quantum optics to my current research, although the bridge is going nowhere and neither sturdy nor accessible at the moment.
July 31, 2025 at 4:10 AM
The long-term goal is to build a bridge from introductory quantum optics to my current research, although the bridge is going nowhere and neither sturdy nor accessible at the moment.
It's useless because it assumes an estimator and you might as well compute the error directly. An inequality is useful only if the bound is easier to compute than the thing you are bounding, or the bound has some independent significance. (n/n)
July 25, 2025 at 4:55 AM
It's useless because it assumes an estimator and you might as well compute the error directly. An inequality is useful only if the bound is easier to compute than the thing you are bounding, or the bound has some independent significance. (n/n)