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April 17, 2008
Gauge Mediation
I was remiss (read: lazy, overworked, or whatever) in not writing, earlier, about Meade, Seiberg and Shih’s paper on gauge mediation. But Patrick Meade was visting this week, so perhaps I can make amends.
There is a huge literature on models of gauge mediated supersymmetry-breaking. And there are a variety of characteristic predictions that emerge from particular classes of models. What these guys do is provide a model-independent characterization of gauge-mediation and try to isolate what features are generic to all models versus those which are special to particular subclasses of models of gauge mediation.
April 13, 2008
Corruption
I must just be unlucky. Here’s how I managed to waste my afternoon.
I committed an update to the Instiki BZR repository, and then did a
bzr log -v
which yielded an ominous
⋮ KnitCorrupt: Knit <bzrlib.knit._KnitAccess object at 0x24b6170> corrupt: While reading {distler@golem.ph.utexas.edu-20080108060135-7ujf0nen62ge328t} got IOError(CRC check failed 3032481332 2792320114)
Yikes!
The .bzr directory is a labyrinth of plain text and gzip-compressed files. Evidently one of the latter was corrupted. But which?
April 12, 2008
Dinosaur
The big news this week, depending on your point of view, is either the progress in Bagger-Lambert theory, or that MathML and SVG have been added to the HTML5 Specification.
As anyone who’s been following this weblog is doubtless bored to tears to hear, serving XHTML is a complicated, finicky, business, requiring jumping through elaborate hoops to ensure well-formedness. It would be so much easier to serve this content as text/html, and rely on the liberal parsing of the HTML parser. Hence it’s very cool that future browsers will support precisely that. As far as I can tell, the only change that would be required, here, is to send the SVG unprefixed. But, since the prefixing is done programmatically (to keep the MTValidate plugin happy), this would be a very easy change. Instiki already emits unprefixed SVG.
I say “as far as I can tell,” because there are no implementations of this days-old addition to the Specification to test against. Eventually, there will be, though I wonder how MathPlayer would handle a change to text/html. There would be a grim irony if IE+MathPlayer became the only browser which needed to be sent application/xhtml+xml.
I look forward to the day when this blog becomes a dinosaur. And, now that MathML is part of the the HTML Spec, I look forward to some more browser implementations.
1 Sam, in his blog post, points out that xml:lang is not supported. This could easily be fixed.
April 1, 2008
April Fool
Back in 1996, I created a Bibtex style file, which would generate hypertex links to the referenced paper at the arXivs. And I coaxed Harv Galic at SPIRES, who was working on a Bibtex output format, to support it.
With a few minor tweaks, this worked quite satisfactorily for over a decade, until the arXivs introduced their new identifier format. The change in format made it rather tricky to craft something that would work seamlessly with both old- and new-style identifiers. And SPIRES’s lackadaisical implementation (lumping everything into the eprint field) didn’t help.
I no longer knew who to contact at SPIRES, and folks at the arXivs didn’t seem too interested in taking up the issue. So things languished … for a year.
But, then, last week, the arXiv Admins contacted me, and the ball started rolling. After some back-and forth discussions, Travis Brooks implemented the new scheme at SPIRES. So, just in time for the 1st anniversary of the new arXiv identifier scheme, there’s a new version of utphys.bst.