On The Calculation Of Unil

  title={On The Calculation Of Unil},
  author={ANDREW RANICKI},
  • Published 2003
Cappell’s codimension 1 splitting obstruction surgery group UNiln is a direct summand of the Wall surgery obstruction group of an amalgamated free product. For any ring with involution R we use the quadratic Poincaré cobordism formulation of the L-groups to prove that Ln(R[x]) = Ln(R) ⊕ UNiln(R;R, R) . We combine this with M. Weiss’ universal chain bundle theory to produce almost complete calculations of UNil∗(Z; Z,Z) and the Wall surgery obstruction groups L∗(Z[D∞]) of the infinite dihedral… CONTINUE READING