automatic continuity of almost multiplicative maps between frechet algebras

Automatic continuity of almost multiplicative maps between Frechet algebras

For Fr$acute{mathbf{text{e}}}$chet algebras $(A, (p_n))$ and $(B, (q_n))$, a linear map $T:Arightarrow B$ is textit{almost multiplicative} with respect to $(p_n)$ and $(q_n)$, if there exists $varepsilongeq 0$ such that $q_n(Tab - Ta Tb)leq varepsilon p_n(a) p_n(b),$ for all $n in mathbb{N}$, $a, b in A$, and it is called textit{weakly almost multiplicative} with respect to $(p_n)$ and $(q_n)$...

Automatic Continuity of Homomorphisms Between Banach algebras and Frechet algebras

Almost n-Multiplicative Maps‎ between‎ ‎Frechet Algebras

For the Fr'{e}chet algebras $(A, (p_k))$ and $(B, (q_k))$ and $n in mathbb{N}$, $ngeq 2$, a linear map $T:A rightarrow B$ is called textit{almost $n$-multiplicative}, with respect to $(p_k)$ and $(q_k)$, if there exists $varepsilongeq 0$ such that$$q_k(Ta_1a_2cdots a_n-Ta_1Ta_2cdots Ta_n)leq varepsilon p_k(a_1) p_k(a_2)cdots p_k(a_n),$$for each $kin mathbb{N}$ and $a_1, a_2, ldots, a_nin A$. Th...

automatic continuity of homomorphisms between banach algebras and frechet algebras

Close operator algebras and almost multiplicative maps

where A,B ⊂ B(H), and the distance between A⊗Mn and B ⊗Mn is measured in B(H) ⊗ Mn ∼= B(H). We also investigate the consequences of “complete closeness”, i.e. what can be said when dcb(A,B) is small? For example, if dcb(A,B) is small, then any projection p ∈ A ⊗ Mn can be suitably approximated by a projection q ∈ B ⊗ Mn, leading an isomorphism K0(A) → K0(B) which maps [p]0 to [q]0. This strateg...