Ronald G. Douglas (1938-2018)
A couple of weeks ago I learned from an American colleague that Ron Douglas passed away. This loss saddens me very much. Ron Douglas was a leader in the Operator Theory community, an inspiring...
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Minimal and maximal matrix convex sets
The final version of the paper Minimal and maximal matrix convex sets, written by Ben Passer, Baruch Solel and myself, has recently appeared online. The publisher (Elsevier) sent us a link through...
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The perfect Nullstellensatz
Question: to what extent can we recover a polynomial from its zeros? Our goal in this post is to give several answers to this question and its generalisations. In order to obtain elegant answers, we...
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Souvenirs from the Red River
Last week I attended the annual Canadian Operator Symposium, better known in its nickname: COSY. This conference happens every year and travels between Canadian universities, and this time it was held...
View ArticlePolya’s three rules of style
In G. Polya‘s book “How to Solve It”, one of the shortest sections is called “Rules of style”. This section contains Polya’s three rules of style, which are worth repeating. “The first rule of style”,...
View ArticleThe day I got tenure
I was on the phone, and there was a knock on my door. I mumbled something and in came the dean. “Oh, I see that you’re busy, I’ll come back later.” I returned to the phone conversation. My mother was...
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The complex matrix cube problem (in “Summer Projects in Mathematics at the...
Next week I will participate as a mentor in the Technion’s Summer Projects in Mathematics. The project I offered is called “Numerical explorations of open problems from operator theory”, and it...
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The complex matrix cube problem summer project – summary of results
In the previous post I announced the project that I was going to supervise in the Summer Projects in Mathematics week at the Technion. In this post I wish to share what we did and what we found in that...
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New paper “Compressions of compact tuples”, and announcement of mistake (and...
Ben Passer and I have recently uploaded our preprint “Compressions of compact tuples” to the arxiv. In this paper we continue to study matrix ranges, and in particular matrix ranges of compact tuples....
View ArticleCourse announcement: Operator Spaces, Operator Algebras and Related Topics...
Next week I will begin teaching a topics course “Topics in Operator Theory – 106435”. This is an advanced graduate course, where “advanced” means that I expect students to be familiar with graduate...
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Topics in Operator Theory, Lecture 1
This is a summary of the first lecture, which was introductory in nature. will always denote a Hilbert space over . will always denote the algebra of bounded operators on . I am interested in operators...
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Topics in Operator Theory, Lecture 2: Dilations of contractions
In this lecture we will study the first chapter in the theory of dilations of contractions. To proceed in our study of operator spaces and operator algebras, the material we will cover is not strictly...
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Topics in Operator Theory, Lecture 3: Dilations of commuting operators
We continue in this lecture to consider dilation theory of contractions. In the theory of Sz.-Nagy and Foias, the main route proceeded from the existence of the minimal isometric and unitary dilations,...
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Topics in Operator Theory, Lecture 4: Pick interpolation via commutant lifting
Finally we reached the point where we can apply the general theory that we developed in the last two weeks to obtain an interesting application to function theory, namely, the Pick interpolation...
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Topics on Operator Theory, Lecture 5 and on
Last week (which was the fourth week, not really the fourth lecture) we finished the proof of Pick’s interpolation theorem, and then I gave a one hour crash course in C*-algebras. The main topics we...
View ArticleNew paper: Distance between reproducing kernel Hilbert spaces and geometry of...
Danny Ofek, Satish Pandey and I just uploaded our new paper “Distance between reproducing kernel Hilbert spaces and geometry of finite sets in the unit ball” to the arxiv. This papers fits into my...
View ArticleSeminar talk by Dor-On: Quantum symmetries in the representation theory of...
NOTE: THE SEMINAR WAS POSTPONED TO DECEMBER 10. On next Thursday the Operator Algebras and Operator Seminar will convene for a talk by Adam Dor-On. Title: Quantum symmetries in the representation...
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Seminar talk by Hartz: How can you compute the multiplier norm?
Happy new year! Next Thursday, January 7th, 2021, Michael Hartz will speak in our Operator Algebras and Operator Theory seminar. Title: How can you compute the multiplier norm? Time: 15:30-16:30 Zoom...
View ArticleSeminar talk by Viselter – Quantum groups: constructions and lattices
Our speaker for next Thursday’s Operator Algebras/Operator Theory Seminar is Ami Viselter (Haifa University). Time: 15:30-16:30 Thursday, February 18, 2021 Title: Quantum groups: constructions and...
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William Arveson
I came back to this old post, and noticed that it is almost ten years since Bill Arveson passed away. It’s hard to believe. Noncommutative Analysis William B. Arveson was born in 1934 and died last...
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