6 papers
Functional a posteriori error estimates for parabolic obstacle problems
Darya E. Apushkinskaya, Sergey I. Repin
The paper is concerned with functional type a posteriori estimates for the initial boundary value problem for a parabolic partial differential equation with an obstacle. We deduce…
Biharmonic obstacle problem: guaranteed and computable error bounds for approximate solutions
Darya E. Apushkinskaya, Sergey I. Repin
The paper is concerned with a free boundary problem generated by the biharmonic operator and an obstacle. The main goal is to deduce a fully guaranteed upper bound of the differenc…
Venttsel boundary value problems with discontinuous data
Darya E. Apushkinskaya, Alexander I. Nazarov, Dian K. Palagachev +1
We study linear and quasilinear Venttsel boundary value problems involving elliptic operators with discontinuous coefficients. On the base of the a priori estimates obtained, maxim…
In Search of Shadows: the First Topological Conference, Moscow 1935
D. E. Apushkinskaya, A. I. Nazarov, G. I. Sinkevich
We discuss some mistakes and curiosities concerned with the celebrated First International Topological Conference in Moscow, 1935.
On the Boundary Point Principle for divergence-type equations
Darya E. Apushkinskaya, Alexander I. Nazarov
We provide some versions of the Zaremba-Hopf-Oleinik boundary point lemma for general elliptic and parabolic equations in divergence form under the sharp requirements on the coeffi…
Vladimir Ivanovich Smirnov (1887-1974)
Darya E. Apushkinskaya, Alexander I. Nazarov
The year 2017 marked the 130th anniversary of the prominent Russian mathematician Vladimir Ivanovich Smirnov. We review some aspects of his life and his mathematical accomplishment…