#### Alladi Ramakrishnan Hall

#### The Euler class group and the orbit space of unimodular rows

#### Mrinal Das

##### ISI-Kolkata

*Let R be a smooth affine domain of dimension d over an infinite*

perfect field k. In this talk we shall describe the relation between the

Euler

class group of R and the Vaserstein-van der Kallen group of elementary

orbits

of unimodular rows over R. We will then show, if k is the field of reals,

how

this relation facilitates computation of the latter group.

Done