报告人:  刘毅       北京大学国际数学中心( BICM)
	 
	时间: 11月10日,下午4:00---5:00
	 
	地点: 交大犀浦校区X2511
	 
	Title:Degree of $L^2$-Alexander torsion for 3-manifolds
	 
	Abstract:For an irreducible orientable compact $3$-manifold $N$ with
empty or incompressible toral boundary, the full $L^2$--Alexander torsion
$\tau^{(2)}(N,\phi)(t)$ associated to any real first cohomology class $\phi$ of
$N$ is represented by a function of a positive real variable $t$. In this talk,
I will show that $\tau^{(2)}(N,\phi)$ is continuous, everywhere positive, and
asymptotically monomial in both ends. Moreover, the degree of
$\tau^{(2)}(N,\phi)$ equals the Thurston norm of $\phi$.