8 citations · 22 across the 9 of their papers we have counts for
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Generalized symmetries of remarkable (1+2)-dimensional Fokker-Planck equation
Dmytro R. Popovych, Serhii D. Koval, Roman O. Popovych
Using an original method, we find the algebra of generalized symmetries of a remarkable (1+2)-dimensional ultraparabolic Fokker-Planck equation, which is also called the Kolmogorov…
Algebraic method of group classification for semi-normalized classes of differential equations
Celestin Kurujyibwami, Dmytro R. Popovych, Roman O. Popovych
We generalize the notion of semi-normalized classes of systems of differential equations, study properties of such classes and extend the algebraic method of group classification t…
Equivalence of diagonal contractions to generalized IW-contractions with integer exponents
Dmytro R. Popovych, Roman O. Popovych
We present a simple and rigorous proof of the claim by Weimar-Woods [Rev. Math. Phys. 12 (2000) 1505-1529] that any diagonal contraction (e.g., a generalized Inönü-Wigner contracti…
Lowest dimensional example on non-universality of generalized Inönü-Wigner contractions
Dmytro R. Popovych, Roman O. Popovych
We prove that there exists just one pair of complex four-dimensional Lie algebras such that a well-defined contraction among them is not equivalent to a generalized IW-contraction…