14 citations · 34 across the 19 of their papers we have counts for
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Schatten class Hankel operators on doubling Fock spaces and the Berger-Coburn phenomenon
Ghazaleh Asghari, Jani A. Virtanen, Zhangjian Hu
Using the notion of integral distance to analytic functions, we give a characterization of Schatten class Hankel operators acting on doubling Fock spaces on the complex plane and u…
Crouzeix's conjecture for classes of matrices
Ryan O'Loughlin, Jani Virtanen
For a matrix which satisfies Crouzeix's conjecture, we construct several classes of matrices from for which the conjecture will also hold. We discover a new link between cy…
Volterra-type inner derivations on Hardy spaces
H. Arroussi, C. Tong, J. A. Virtanen +1
A classical result of Calkin [Ann. of Math. (2) 42 (1941), pp. 839-873] says that an inner derivation maps the algebra of bounded operators on a Hilbert sp…
On the Berger-Coburn phenomenon
Zhangjian Hu, Jani A. Virtanen
In their previous work, the authors proved the Berger-Coburn phenomenon for compact and Schatten class Hankel operators on generalized Fock spaces when , th…
Essential positivity
A. Perälä, J. A. Virtanen
We define essentially positive operators on Hilbert space as a class of self-adjoint operators whose essential spectra is contained in the nonnegative real numbers and describe the…
On the product formula for Toeplitz and related operators
Jani A. Virtanen
In this note known formulas for the product of Toeplitz operators are revisited in the context of their applications to the study of Fredholmness, boundedness of Toeplitz products,…