Rumour has it (see for example here or here)

that Carolyn Dean proved the Jacobian

conjecture in two variables!!!

Melvin Hochster seems to have

checked the proof and is convinced it is ok. Here is what he mailed to

seminar participants

The Jacobian conjecture

in the plane has been an open problem since 1939 (Keller). The simple

statement is this: given a ring map $F$ of $C[x,y]$ (the polynomial ring

in two variables over the complex numbers $C$) to itself that fixes $C $

and sends $x, y$ to $f, $g, respectively, $F$ is an automorphism if and

only if the Jacobian determinant $f_x g_y – f_y g_x$ is a nonzero

element of $C$. The condition is easliy seen to be necessary.

Sufficiency is the challenge.

Carolyn Dean has

proved the conjecture and will give a series of talks on it beginning

Thursday, December 2, 3-4 pm, continuing on December 9 and December 16.

Because there have been at least five published incorrect proofs and

innumerable incorrect attempts, any announcement of a proof tends to be

received with skepticism. I have spent approximately one hundred hours

(beginning in mid-August) checking every detail of the argument. It is

correct.

Many congratulations Carolyn and I hope to see you once

again somewhere, sometime.