Teoria calitativă a sistemelor de ecuaţii differenţiale; teoria invarianţilor algebrici; elaborarea de algoritme şi programe pentru utilizarea polinoamelor invariante
Lucrări importante
Global classification of the planar Lotka-Volterra differential systems according to the configurations of invariant straight lines Journal of Fixed Point Theory and Applications, 8 (2010), 177--245 (coautor D. Schlomiuk).
Quadratic systems with a rational first integral of degree three: a complete classification in the coefficient space $\mathbb{R}^{12}$. Rendiconti del Circolo Matematico di Palermo 59 (2010), 419--449 (coautori: J. Artes, J.Llibre).
Bifurcation diagrams and moduli spaces of planar quadratic vector fields with invariant lines of total multiplicity four and having exactly three real singularities at infinity. Qualitative Theory of Dynamical Systems, 9 (2010), No. 1-2, 251-300 (coautor D. Schlomiuk).
Quadratic systems with a polynomial first integral: a complete classification in the coefficient space $\mathbb{R}^{12}$. J. Differential Equations, 246 (2009), 3535--3558 (coautori: J. Artes, J.Llibre).
Integrals and phase portraits of planar quadratic differential systems with invariant lines of at least five total multiplicity. Rocky Mountain Journal of Mathematics, Vol. 38 (2008), No. 6, 2015--2075 (coautor D. Schlomiuk).
When singular points determine quadratic systems. Electronic Journal of Differential Equations, Vol. 2008 (2008), No. 82, 1--37. (coautori: J. Artes, J.Llibre).
The full study of planar quadratic differential systems possessing a line of singularities at infinity. Journal of Dynamics and Diff. Equations, 20 (2008), No. 4, 737-775 (coautor D. Schlomiuk).
The types of the singular points for quadratic system: a complete solution of the problem in the coefficient space $\mathbb{R}^{12}$. International Journal of Bifurcation Theory and Chaos, 18, No.2 (2008), 1301--1373 (coautori: J. Artes, J.Llibre).
Integrals and phase portraits of planar quadratic differential systems with invariant lines of total multiplicity four Buletinul A.ş.M., Matematica, No. 1(56), 2008, 27--83 (coautor D. Schlomiuk).
Planar quadratic differential systems with invariant straight lines of total multiplicity four. Nonlinear Anal., 68 (2008), No. 4, 681-715 (coautor D. Schlomiuk).
Quadratic systems with a rational first integral of degree 2: a complete classification in the coefficient space $\mathbb{R}^{12}$. Rendiconti Circolo Matematico di Palermo, Serie II, T. LVI (2007), 417--444 (coautori: J. Artes, J.Llibre).
Planar cubic polynomial differential systems with the maximum number of invariant straight lines. Rocky Mountain J. Math., 36, No.4, 2006, 1301--1373 (coautor: J.Llibre).
Geometry of quadratic differential systems in the neighbourhood of the line at infinity. J. Differential Equations, 215 (2005) 357--400 (coautor D. Schlomiuk).
Apartenenţa la societăţi, redacţii
Redactor responsabil al revistei periodice de matematică „Buletinul Academiei de ştiinţe a Moldovei. Matematica” (începând cu anul 1993).
Societatea Matematică din Republica Moldova (SMRM).
Distincţii
Laureat al Premiului „Academician C.Sibirschi” pe anul 2000 pentru ciclul de lucrări „Aplicarea polinoamelor invariante în studiul calitativ al sistemelor de ecuaţii diferenţiale”.
Laureat al Premiului Republican pentru tineri cercetători pentru ciclul de lucrări în domeniul invarianţilor algebrici ai sistemelor diferenţiale (1978).
Activitate
Conducător adjunct al seminarului ştiinţific „Teoria calitativă a ecuaţiilor diferenţiale” de la Universitatea de Stat din Moldova.
Membru al Consiliului ştiinţific al IMI.
Publicaţii în Computer Science Journal of Moldova, Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica şi Quasigroups and Related Systems