Area product and mass formula for Kerr–Newman–Taub–NUT spacetime

Trotter's product formula for projections

where the limit is taken in the strong operator topology (see e.g. Goldstein [G, Theorem 8.12.] or ChernofF [C] for a comprehensive treatment of product formulas). Now let P G £ (E) be a contractive projection. Then we may consider P as a constant degenerate semigroup on E. It is interesting to know under which circumstances the limit in (1) exists if we replace e by P. More precisely, we ask f...

Trotter’s product formula for projections

The aim of this paper is to examine the convergence of Trotter’s product formula when one of the C0-semigroups is replaced by a projection (which can always be regarded as a constant degenerate semigroup). The motivation to study Trotter’s formula in this setting arises from the fact that for ’nice’ open sets Ω ∈ R the C0-semigroup on L(Ω) generated by the Laplacian with Dirichlet boundary cond...

Zeno product formula revisited

We introduce a new product formula which combines an orthogonal projection with a complex function of a non-negative operator. Under certain assumptions on the complex function the strong convergence of the product formula is shown. Under more restrictive assumptions even operator-norm convergence is verified. The mentioned formula can be used to describe Zeno dynamics in the situation when the...

A Formula for the Direct Product of Crossed Product Algebras

tive radius r. Let the center Xo be the sequence {&?}, and let 5 be chosen so large that 2~~ + 2~ s 2 + • • • k Q s. If we define xi as (ki, &2> ' * • » $j j8+i, is+2, • • • ), then xi belongs to K and limn fn(xi) = + °°Consequently xi cannot be a point of Up and this contradiction establishes U as a set of the f...

The Co-area Formula