Sunday, January 22, 2006

never mind: i am an idiot.

F*ck. I am a f*cking idiot and ignorant of obvious facts, but in a good way. You see, in an earlier post I had written that

.. I'm stuck on a small but important part of the very last argument.

It concerns Sobolev functions, as well as functions of bounded variation (BV for short). The theory of BV functions is nice and well-developed, but to be honest I never thought that I'd actually use them. It's like having your bike stolen: you know it's possible but you never expect it to happen.


Well, surprise of surprises. I was overthinking it, and my instincts were right: there's no need to apply the machinery of BV functions, after all. In fact, an elementary fact about Sobolev functions was all I needed:

Sobolev functions on the real line have absolutely continuous representatives.

Maybe I should have listened to myself more carefully when I was giving that Student Analysis Seminar talk! q:

2 comments:

Anonymous said...

thats the binary nature of math; its either blindingly obvious or completely impenetrable. many a time have i had similar thoughts. its part of the territory.

janus said...

aye, agreed.

now this is a silly neurosis of mine, but sometimes i get what seems like a good idea, but insist on waiting a day or two before trying it out. i might work on other matters, in the meanwhile.

the logic is that if it hasn't been tested, then as a pure probability, there could be a chance that it works.

being that most of my "good" ideas either fail or have been pondered before by wiser persons, it's a pleasant fiction to have around.