Noncommutative Analysis

Month: December, 2012

Happy new year!

It is good to start the new year with a positive headline in my blog. So to any occasional visitor of this blog who comes from afar: if this is your new year, then I wish you a happy new year!

I will spend the next two weeks in Indian Statistical Institute (Bangalore) at the conference and workshop Recent Advances in Operator Theory and Operator Algebras.

Some time ago I made a rule for myself that in conferences I have to choose one talk which interests me very much and which I later have to go and try to understand better. So every night I think of the talks that were that day, and choose a candidate from that day, and in the end I compare my candidates and pick one talk (or speaker). Then I promise myself to go read the paper/s the talk was based on. Even if I later don’t find the time to read the paper (it has also happened to me once that the paper was still unavailable, even in pre-print form, which I found annoying), the process of searching for that talk helps me stay alert and open minded during the conference.

I will try to play this trick on myself again, and I hope to be able to report after I return from Bangalore on one of the talks or the mini-courses.

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Worse than Elsevier, worse than …

I recently received the following email from Cambridge University Press:

Submit your article online now

Dear Dr Shalit
We are delighted to announce that the online submission systems forForum of Mathematics, Pi and Forum of Mathematics, Sigma are now live. Forum of Mathematics offers fully open access publication combined with peer-review standards set by an international editorial board of the highestcalibre, and all backed by Cambridge University Press and our commitment to quality.
Don’t forget:
  • For the first three years Cambridge University Press will waive the publication charges
  • After this, a publication charge for authors will be set at £500/$750, this charge being based on real publishing costs and overheads
etc., …,

Authors benefit from:• Peer-review by experts

• Free, permanent, worldwide access to your article
• High editorial and production service
• The author will hold the copyright of published papers via a Creative Commons license
• State-of-the-art online hosting, including forward reference linking and extensive content alerts
• Free online colour
• Global dissemination of your paper
Kind regards,
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Cambridge Journals

To which I replied:

Dear ************,

I will not submit a journal to FOM because I strongly object to author processing charges, and your journal endorses this practice.

Kind regards,
Orr Shalit

I blogged on this subject before. I just want to add here that in my opinion, the fact that FOM does no collect money from authors for the first three years does not make it better than other predatory journals, it makes it worse. Cambridge University Press uses its prestige to endorse the practice of author charges, and it uses its money to make it look sustainable, to get us used to the idea.

I really hope that mathematicians will not flock behind the leaders of this initiative. The overall impression I get is that my hopes are hopeless. So here is one last cry: you are going in the wrong direction! Even if dpearments change so much that everybody gets a fair budget for publishing (which I find hard to believe), do we really need another item in our academic lives where we have to fill in a form to get $750 for a simple academic activity? And how can one possibly consider submitting a paper to FOM when one can submit to some other journal for free and save one’s department $750?

 Here is an example of how to do it right.

Advanced Analysis, Notes 15: C*-algebras (square root)

This post contains some make–up material for the course Advanced Analysis. It is a theorem about the positive square root of a positive element in a C*-algebra which does not appear in the text book we are using. My improvisation for this in class came out kakha–kakha, so here is the clarification.

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The remarkable Hilbert space H^2 (part III – three open problems)

This is the last in the series of three posts on the d–shift space, which accompany/replace the colloquium talk I was supposed to give. The first two parts are available here and here. In this post I will discuss three open problems that I have been thinking about, which are formulated within the setting of H^2_d.

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Matthew Kennedy awarded CMS 2012 Doctoral Prize

One of the nicest things that happen on math blogs is that people write expository posts on other people’s work. Tim Gowers and Terry Tao have set a fine example in their expositions of the works of Fields Medalists or Abel Prize laureates. These are among the most interesting and important posts out there, I think.

Recently, at the Canadian Mathematical Society’s Winter Meeting, Matthew Kennedy was awarded the CMS 2012 Doctoral Prize (at the meeting several other prizes were awarded by the CMS as you can see on the meeting’s homepage). See here for the media release, and here for a description of the prize and a list of past recipients.

Matt gave a plenary lecture at the CMS meeting surveying (some of) his work. Here are the slides, which are certainly worth looking at (thanks to Matt for allowing me to post them). Note that on the last slide there are photos of two gentlemen with no captions; these are Ken Davidson (on the left, Matt’s PhD supervisor) and Heydar Radjavi (Matt’s undergraduate research supervisor).

In this post I will describe a couple of Matt’s first really big results, one of which didn’t make it into his talk. These are the existence of wandering vectors for (certain) free semigroup algebras, and the reflexitivity of free semigroup algebras. These result appeared in the tour-de-force paper “Wandering vectors and the reflexivity of free semigroup algebras”; here are links to arxiv, mathscinet, and the official version in CrelleRead the rest of this entry »

The remarkable Hilbert space H^2 (Part II – multivariable operator theory and model theory)

This post is the second post in the series of posts on the d–shift space, a.k.a. the Drury–Arveson space, a.k.a. H^2_d (see this previous post about the space H^2).

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The remarkable Hilbert space H^2 (Part I – definition and interpolation theory)

This series of posts is based on the colloquium talk that I was supposed to give on November 20, at our department. As fate had it, that week studies were cancelled.

Several people in our department thought that it would be a nice idea if alongside the usual colloquium talks given by invited speakers which highlight their recent achievements, we would also have some talks by department members that will be more of an exposition to the fields they work in. So my talk was supposed to be an exposition to the setting in which much of the research I do goes on.

The topic of the “talk”  is the Hilbert space H^2_d. There will be three parts to this series:

  1. Definition and interpolation theory. 
  2. Multivariate operator theory and model theory
  3. Current research problems

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