3 papers
math.FA2026
Hardy-type norms of matrices
Leonid V. Kovalev
We show that the function that assigns to each square matrix the geometric mean of over all unit vectors is a norm. The same holds for means with . Some…
math.CV2025
Sharp bounds for some segments of bounded power series
Leonid V. Kovalev
We obtain sharp upper bounds for three-term segments of a bounded power series. Along the way we show that the Taylor polynomials of a certain algebraic function do not vanish in t…
math.CV2024
A sharp bound on the number of self-intersections of a trigonometric curve
Sergei Kalmykov, Leonid V. Kovalev
We obtain a sharp bound on the number of self-intersections of a closed planar curve with trigonometric parameterization. Moreover, we show that a generic curve of this form is nor…