Program v akademickém roce 2018/2019
25. 4. 2019
RNDr. Petr Vojčák, Ph.D., Nonlocal symmetries, conservation laws, and recursion operators of the Veronese web equation
18. 4. 2019
doc. RNDr. Artur Sergyeyev, Ph.D., The Gardner method for symmetries (after the paper by A. Rasin and J. Schiff)
15. 2. 2019
Roman Popovych, D.Sc. (University of Vienna, Rakousko), Extended symmetry analysis of isothermal no-slip drift flux model II
Jedná se o volné pokračování předchozí přednášky.
Seminář proběhne v mimořádném termínu v pátek 15. 2. od 14.00.
7. 2. 2019
Roman Popovych, D.Sc. (University of Vienna, Rakousko), Extended symmetry analysis of isothermal no-slip drift flux model
Abstrakt:
We perform extended group analysis for a system of differential equations modeling an isothermal no-slip drift flux. The maximal Lie invariance algebra of this system is proved to be infinite-dimensional. We also find the complete point symmetry group of this system, including discrete symmetries, using the megaideal-based version of the algebraic method. Optimal lists of one- and two-dimensional subalgebras of the maximal Lie invariance algebra in question are constructed and employed for obtaining reductions of the system under study. Since this system contains a subsystem of two equations that involves only two of three dependent variables, we also perform group analysis of this subsystem. The latter can be linearized by a composition of a fiber-preserving point transformation with a two-dimensional hodograph transformation to the Klein-Gordon equation. We also employ both the linearization and the generalized hodograph method for constructing the general solution of the entire system under study. We find inter alia genuinely generalized symmetries for this system and present the connection between them and the Lie symmetries of the subsystem we mentioned earlier. Hydrodynamic conservation laws and their generalizations are also constructed.
This is joint work with S. Opanasenko, A. Bihlo and A. Sergyeyev.
6. 12. 2018
doc. RNDr. Artur Sergyeyev, Ph.D. The Gardner method for symmetries (after Rasin and Schiff)
Přednáška začne v 14.50.
22. 11. 2018
Priscila Leal da Silva, Ph.D. (Universidade Federal de São Carlos, Brazílie), Classification of bounded travelling wave solutions of Dullin-Gotwald-Holm equations
Abstrakt:
In this talk we will discuss the problem of existence of bounded traveling wave solutions of Dullin-Gottwald-Holm equations. The classification presents both smooth and weak solutions of the equations under consideration.
15. 11. 2018
Roman Popovych, D.Sc. (University of Vienna, Rakousko), Effective generalized equivalence groups for classes of differential equations
Seminář prof. Popovyche začne ve 14:30.
1. 11. 2018
Igor Leite Freire, D.Sc. (UFABC, Brazílie), Some results on the rotation Camassa-Holm equation
Abstrakt:
Recently, a mathematical model of the equatorial water waves with Coriollis effect was derived. This model is a generalization of the Dullin-Gottwald-Holm equation, which itself is a generalization of the Camassa-Holm equation. In this talk we shall discuss some results on the model in question, known as the rotation Camassa-Holm equation.
18. 10. 2018
Roman Popovych, D.Sc. (University of Vienna, Rakousko), Generalized symmetries and conservation laws of (1+1)-dimensional Klein--Gordon equation
Abstrakt:
We explicitly find the algebra of generalized symmetries of the (1+1)-dimensional Klein--Gordon equation, which allows us to describe this algebra in terms of the universal enveloping algebra of the essential Lie invariance algebra of the Klein--Gordon equation. Then we single out variational symmetries of this equation and compute the space of its local conservation laws.
11. 10. 2018
doc. RNDr. Artur Sergyeyev, Ph.D., Integrable systems in 4D from contact geometry
Abstrakt:
In this talk we present a survey of results from the paper A. Sergyeyev, New integrable (3+1)-dimensional systems and contact geometry, Lett. Math. Phys. 108 (2018), no. 2, 359-376.
4. 10. 2018
Igor Leite Freire, D.Sc. (UFABC, Brazílie), A look on some results about Camassa-Holm type equations
Abstrakt:
We discuss some results on families of equations including the Camassa-Holm and Novikov equations, and the generalizations thereof. The talk is based on joint works with S.C. Anco, P. L. da Silva, and D.C. Ferraioli.
26. 9. 2018
Seminář je spojen se slavnostním seminářem prof. Smítala a doc. Štefánkové - zahájení mimořádně od 12:00 v aule:
Martin Černohorský, Úspěch historie a lingvistiky při rehabilitaci Newtona a jeho prvního axiomu pohybu vykládaného po tři staletí neoprávněně jako jen pouhý zvláštní případ druhého axiomu (kolokviální přednáška).
Semináře se obvykle konají ve čtvrtek od 14.00 hod. v budově Matematického ústavu, Na Rybníčku 1 v Opavě, v místnosti R1. Všichni zájemci jsou srdečně zváni.