Higher order $\Sc^2$-differentiability and application to Koplienko trace formula

Clément Coine, Christian Le Merdy, Anna Skripka +1

Let $A$ be a selfadjoint operator in a separable Hilbert space, $K$ a selfadjoint Hilbert-Schmidt operator, and $f\in C^n(\mathbb{R})$. We establish that $\phi (t)=f(A+tK)-f(A)$ is $n$…