25.07.2013 Views

Mikhail SODIN

Mikhail SODIN

Mikhail SODIN

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

✬<br />

Part V: Steps in the proof of Theorem I<br />

Step 1: Some integral geometry<br />

Notation: N(u, r; F ) the number of connected components of Z(F )<br />

contained in the open ball B(u, r)<br />

¯N(u, r; F ) the number of connected components of Z(F ) that intersect<br />

the closed ball B(u, r)<br />

Lemma: For 0 < r < R < ∞,<br />

<br />

<br />

N(u, r; F )<br />

du ≤ N(R; F ) ≤<br />

volB(r)<br />

✫<br />

B(R−r)<br />

We apply this with 1 ≪ r ≪ R.<br />

B(R+r)<br />

¯N(u, r; F )<br />

volB(r) du<br />

Notation: (τvF )(u)=F (u + v) (translation). Then N(u, r; F )=N(r; τuF )<br />

Observe: ¯ N(r; F ) − N(r; F ) ≤ N(r; F ) def<br />

= # of critical pts of F ∂B(r)<br />

21<br />

to be continued on the next slide<br />

✩<br />

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!