Chennai Mathematical Institute


12.00 noon, NKN Hall
Some Applications of G_a-actions on Affine Varieties

Amartya Kumar Dutta
ISI, Calcutta.


The concept of G_a-action can been reformulated in the convenient ring-theoretic language of ``locally nilpotent derivation'' (in characteristic zero) and ``exponential map'' (in arbitrary characteristic). Results on locally nilpotent derivations and exponential maps have played a crucial role in some of the breakthroughs in affine algebraic geometry during the past two decades including Makar-Limanov's result on the nontriviality of the Russell-Koras threefold and Neena Gupta's result on the Zariski Cancellation Problem. In this talk we shall highlight some of these applications of locally nilpotent derivations and exponential maps.