01.01.02 (Differential equations, dynamical systems, and optimal control)
Birth date:
6.02.1940
Keywords:
differential equations on networks,
differentiation and integration with respect to the measure,
Green function,
multipoint and non-standard boundary value problems,
oscillation spectral theorems,
Tchebyshev and Markov systems,
positive operators in the space with a cone,
focusing.
Subject:
Differential equations on networks. The concept of differential equation on network as a special type of differential equation (intermediate between ordinary and partial differential equations), the maximum principle established, the solvability of boundary value problems is investigated, Green function is constructed, the complete analugue of the theory of disconjugacy is developed, and for neworks of tree-type the oscillation structure of the spectrum is proved. Multipoint and non-standard boundary value problems. The estimates of Green function are obtained, the technique of normalising of Green function by the sign-changing weight is developed, oscillation theorems are obtained. Positive operators in the space with a cone. Discovered the property which called later the focusing one, the connection of this property with the estimate of the spectral gap is proved. Tchebyshev and Markov systems. The counterexample to the theorem of M. A. Rutman on integral representation of the Markov system is discovered. To repair the possibility of such representation the technique of the differentiation and integration with respect to the fractional measure is developed. Differentiation and integration with respect to the measure. The technique of the differentiation and integration with respect to the fractional measure applying to the analysis of multipoint discontinupus boundary problems and boundary problems on networks is developed. For equations of the second order with differentiation with respect to the measure the complete analogue of Sturm–Liouville theory is obtained.
Biography
Graduated from Voronezh State University (Mathematical department) in 1961. Candidate (Ph.D.) thesis "On the second solutions of nonlinear equations in the space with a cone" — 1967. Doctor thesis "Problems of the qualitative theory of Vallee–Poussin boundary value problem" — 1981. About 200 papers.
Director of Research Institute of Mathematics attached to Voronezh State University (1986–1998), Honour Scientist of Russian Federation, State Reseach Maitenance for Outstanding Scientists (1997–2000, 2001^ndash;2004), AMS member, fellowship of IBC.
Main publications:
Pokornyi Yu. V., Krasnoselskii M. A. Nenulevye resheniya uravnenii s silnymi nelineinostyami // Matem.zametki, 1969. T. 5, vyp. 2. S. 253–260.
Pokornyi Yu. V., Lazarev K. P. Nekotorye ostsillyatsionnye teoremy dlya mnogotochechnykh zadach // Differents. uravneniya. 1987. T. 23, # 4. S. 658–670.
Borovskikh A. V., Pokornyi Yu. V. Sistemy Chebysheva–Khaara v teorii razryvnykh yader Kelloga // Uspekhi matem. nauk. 1994. T. 49, # 3. S. 3–42.
Pokornyi Yu. V., Penkin O. M., Pryadiev V. L. O nelineinoi kraevoi zadache na grafe // Differents. uravneniya. 1998. T. 34, # 5. S. 629–637.
Pokornyi Yu. V. Integral Stiltesa i proizvodnye po mere v obyknovennykh differentsialnykh uravneniyakh // Dokl. AN. 1999. T. 364, # 2. S. 167–169.
Yu. V. Pokornyi, Zh. I. Bakhtina, “On the Stieltjes Procedure for Closing Gaps in Time Scales”, Mat. Zametki, 86:5 (2009), 733–735; Math. Notes, 86:5 (2009), 690–692
Yu. V. Pokornyi, E. V. Gulynina, T. V. Perlovskaya, “The Hicks property for a variational problem on a graph”, Izv. Vyssh. Uchebn. Zaved. Mat., 2008, no. 10, 48–54; Russian Math. (Iz. VUZ), 52:10 (2008), 40–45
3.
Yu. V. Pokornyi, M. B. Zvereva, S. A. Shabrov, “Sturm–Liouville oscillation theory for impulsive problems”, Uspekhi Mat. Nauk, 63:1(379) (2008), 111–154; Russian Math. Surveys, 63:1 (2008), 109–153
Yu. V. Pokornyi, “Zeros of the Green's function for the de la Vallée-Poussin problem”, Mat. Sb., 199:6 (2008), 105–136; Sb. Math., 199:6 (2008), 891–921
Yu. V. Pokornyi, Zh. I. Bakhtina, A. S. Ishchenko, “On solvability of certain classes of irregular the second order variation problems”, Izv. Saratov Univ. Math. Mech. Inform., 7:2 (2007), 32–36
Yu. V. Pokornyi, M. B. Zvereva, A. S. Ishchenko, S. A. Shabrov, “An Irregular Extension of the Oscillation Theory of the Sturm–Liouville Spectral Problem”, Mat. Zametki, 82:4 (2007), 578–582; Math. Notes, 82:4 (2007), 518–521
Yu. V. Pokornyi, I. Yu. Pokornaya, V. L. Pryadiev, N. N. Ryabtseva, “Integration in Variational Inequalities on Spatial Grids”, Mat. Zametki, 81:6 (2007), 904–911; Math. Notes, 81:6 (2007), 810–816
Yu. V. Pokornyi, M. B. Zvereva, S. A. Shabrov, “Some questions of the qualitative theory of nonsmooth Sturm-Liouville problems”, Tr. Semim. im. I. G. Petrovskogo, 26 (2007), 255–274; J. Math. Sci. (N. Y.), 143:4 (2007), 3342–3354
2006
9.
Yu. V. Pokornyi, E. V. Gulynina, M. B. Zvereva, “The Influence function is Simpler
and Better than Green's Function
for a Generalized Stieltjes String”, Mat. Zametki, 80:1 (2006), 149–153; Math. Notes, 80:1 (2006), 146–150
2004
10.
Yu. V. Pokornyi, V. L. Pryadiev, “Some problems of the qualitative Sturm–Liouville theory on a spatial network”, Uspekhi Mat. Nauk, 59:3(357) (2004), 115–150; Russian Math. Surveys, 59:3 (2004), 515–552
Yu. V. Pokornyi, T. V. Beloglazova, E. V. Dikareva, T. V. Perlovskaya, “Green Function for a Locally Interacting System of Ordinary Equations of Different Orders”, Mat. Zametki, 74:1 (2003), 146–149; Math. Notes, 74:1 (2003), 141–143
Yu. V. Pokornyi, T. V. Beloglazova, K. P. Lazarev, “On a Class of Ordinary Differential Equations of Various Orders on a Graph”, Mat. Zametki, 73:3 (2003), 469–470; Math. Notes, 73:3 (2003), 440–442
A. W. Komarov, O. M. Penkin, Yu. V. Pokornyi, “On the spectrum of a uniform network of strings”, Izv. Vyssh. Uchebn. Zaved. Mat., 2000, no. 4, 23–27; Russian Math. (Iz. VUZ), 44:4 (2000), 21–25
Yu. V. Pokornyi, R. Mustafokulov, “On the positivity of the Green function of linear boundary value problems for fourth-order equations on a graph”, Izv. Vyssh. Uchebn. Zaved. Mat., 1999, no. 2, 75–82; Russian Math. (Iz. VUZ), 43:2 (1999), 71–78
O. M. Penkin, Yu. V. Pokorny, “On incompatible inequalities for elliptic equations on stratified sets”, Differ. Uravn., 34:8 (1998), 1107–1113; Differ. Equ., 34:8 (1998), 1111–1117
Yu. V. Pokorny, O. M. Penkin, V. L. Pryadiev, “A nonlinear boundary value problem on a graph”, Differ. Uravn., 34:5 (1998), 629–637; Differ. Equ., 34:5 (1998), 631–638
Yu. V. Pokorny, K. P. Lazarev, T. M. Gareeva, “On the spectral properties of some nonlocal boundary value problems”, Differ. Uravn., 34:1 (1998), 45–49; Differ. Equ., 34:1 (1998), 44–48
1997
19.
Yu. V. Pokorny, R. Mustafokulov, “On the positive invertibility of some boundary value problems for a fourth-order equation”, Differ. Uravn., 33:10 (1997), 1358–1365; Differ. Equ., 33:10 (1997), 1364–1371
Yu. V. Pokornyi, O. Yu. Litmanovich, V. P. Plaksina, “On multivalued differentials of piecewise-smooth functions”, Izv. Vyssh. Uchebn. Zaved. Mat., 1996, no. 11, 73–84; Russian Math. (Iz. VUZ), 40:11 (1996), 70–81
21.
O. M. Penkin, Yu. V. Pokornyi, “On some qualitative properties of equations on a one-dimensional cell complex”, Izv. Vyssh. Uchebn. Zaved. Mat., 1996, no. 11, 57–64; Russian Math. (Iz. VUZ), 40:11 (1996), 54–61
Yu. V. Pokornyi, V. L. Pryadiev, A. Al-Obeid, “Oscillation properties of the spectrum of a boundary value problem on a graph”, Mat. Zametki, 60:3 (1996), 468–470; Math. Notes, 60:3 (1996), 351–353
O. M. Penkin, Yu. V. Pokornyi, “On some qualitative properties of equations on a one-dimensional $CW$-complex”, Mat. Zametki, 59:5 (1996), 777–780; Math. Notes, 59:5 (1996), 562–565
A. V. Borovskikh, R. Mustafokulov, K. P. Lazarev, Yu. V. Pokorny, “On a class of fourth-order differential equations on a
three-dimensional network”, Dokl. Akad. Nauk, 345:6 (1995), 730–732
Yu. V. Pokorny, “On a quasidifferential equation generated by a continuous
Chebyshev system”, Dokl. Akad. Nauk, 345:2 (1995), 171–174
26.
A. V. Borovskikh, K. P. Lazarev, Yu. V. Pokornyi, “On the Kellogg kernels in discontinuous problems”, Trudy Mat. Inst. Steklov., 211 (1995), 102–120; Proc. Steklov Inst. Math., 211 (1995), 92–108
A. V. Borovskikh, K. P. Lazarev, Yu. V. Pokorny, “Oscillatory spectral properties of discontinuous boundary value
problems”, Dokl. Akad. Nauk, 335:4 (1994), 409–412; Dokl. Math., 49:2 (1994), 328–333
Yu. V. Pokorny, “On an integral representation of Markov systems”, Dokl. Akad. Nauk, 335:1 (1994), 18–20; Dokl. Math., 49:2 (1994), 229–232
29.
I. G. Karelina, Yu. V. Pokornyi, “On the Green function for a boundary value problem on a graph”, Differ. Uravn., 30:1 (1994), 41–47; Differ. Equ., 30:1 (1994), 35–40
A. V. Borovskikh, Yu. V. Pokornyi, “Chebyshev–Haar systems in the theory of discontinuous Kellogg kernels”, Uspekhi Mat. Nauk, 49:3(297) (1994), 3–42; Russian Math. Surveys, 49:3 (1994), 1–42
Yu. V. Pokornyi, A. V. Borovskikh, “On the Kellogg theorem for discontinuous Green functions”, Mat. Zametki, 53:1 (1993), 151–153; Math. Notes, 53:1 (1993), 110–111
Yu. V. Pokorny, I. G. Karelina, “On the Green function for the Dirichlet problem on a graph”, Dokl. Akad. Nauk SSSR, 318:3 (1991), 542–544; Dokl. Math., 43:3 (1991), 732–734
Yu. V. Pokornyi, I. G. Karelina, “Nonlinear comparison theorems on graphs”, Mat. Zametki, 50:2 (1991), 155–157; Math. Notes, 50:2 (1991), 879–880
1989
34.
Yu. V. Pokorny, O. M. Penkin, “Sturm theorems for equations on graphs”, Dokl. Akad. Nauk SSSR, 309:6 (1989), 1306–1308; Dokl. Math., 40:3 (1990), 640–642
Yu. V. Pokorny, K. P. Lazarev, T. M. Gareeva, “Conditions of V. A. Il'in type for the solvability of nonlocal boundary value problems for ordinary differential equations”, Dokl. Akad. Nauk SSSR, 304:6 (1989), 1298–1302; Dokl. Math., 39:1 (1989), 210–213
36.
Yu. V. Pokornyi, K. P. Lazarev, T. M. Gareeva, “Nonlocal boundary value problems for ordinary differential equations”, Differ. Uravn., 25:8 (1989), 1321–1332; Differ. Equ., 25:8 (1989), 936–945
37.
Yu. V. Pokornyi, O. M. Penkin, “Comparison theorems for equations on graphs”, Differ. Uravn., 25:7 (1989), 1141–1150; Differ. Equ., 25:7 (1989), 802–809
Yu. V. Pokornyĭ, I. Yu. Shurupova, “The Green function of a quasi-interpolation multipoint problem”, Izv. Vyssh. Uchebn. Zaved. Mat., 1989, no. 9, 46–52; Soviet Math. (Iz. VUZ), 33:9 (1989), 46–51
1988
39.
O. M. Penkin, Yu. V. Pokornyi, “On a boundary value problem on a graph”, Differ. Uravn., 24:4 (1988), 701–703
Yu. V. Pokornyi, S. V. Smitskikh, “Inversion of the oscillatory property of focusing operators”, Mat. Zametki, 20:5 (1976), 753–760; Math. Notes, 20:5 (1976), 980–984
1975
48.
Yu. V. Pokornyi, “Second solutions of multipoint boundary value problems with convex nonlinearities”, Differ. Uravn., 11:10 (1975), 1801–1810
P. P. Zabreiko, M. A. Krasnosel'skii, Yu. V. Pokornyi, “On a class of linear positive operators”, Funktsional. Anal. i Prilozhen., 5:4 (1971), 9–17; Funct. Anal. Appl., 5:4 (1971), 272–279
Yu. V. Pokornyi, “Inequality for second characteristic values of positive operators of certain classes”, Mat. Zametki, 9:1 (1971), 27–33; Math. Notes, 9:1 (1971), 17–20
M. A. Krasnosel'skii, Yu. V. Pokornyi, “Non-zero solutions of equations with strong nonlinearities”, Mat. Zametki, 5:2 (1969), 253–260; Math. Notes, 5:2 (1969), 153–157
Yu. V. Pokornyi, “On estimates for the Green's function for a multipoint boundary problem”, Mat. Zametki, 4:5 (1968), 533–540; Math. Notes, 4:5 (1968), 810–814
Yu. V. Pokornyi, N. V. Titova, “Should one Study Higher Mathematics?”, Math. Ed., 2008, no. 3(47), 50–55
2005
55.
P. L. Ul'yanov, Yu. V. Pokornyi, S. A. Shabrov, “Voronezh Winter Mathematical School
“Modern Methods in Theory of Functions and Adjacent Problems””, Uspekhi Mat. Nauk, 60:3(363) (2005), 185–186
V. A. Il'in, Yu. V. Pokorny, A. V. Borovskikh, “Pontryagin Readings-XIV at Voronezh Spring Mathematical School “Modern Methods in Qualitative Theory of Boundary Value Problems””, Differ. Uravn., 39:11 (2003), 1574; Differ. Equ., 39:11 (2003), 1661–1662
P. L. Ul'yanov, Yu. V. Pokornyi, A. V. Borovskikh, “Contemporary methods in theory of functions and adjacent problems”, Uspekhi Mat. Nauk, 58:4(352) (2003), 177–178
Yu. V. Pokornyi, P. L. Ul'yanov, A. V. Borovskikh, “Voronezh Winter Mathematical School “Modern Methods in Theory of Functions and Adjacent Problems””, Uspekhi Mat. Nauk, 56:4(340) (2001), 185–186
P. L. Ul'yanov, Yu. V. Pokornyi, A. V. Borovskikh, ““Modern Methods in Theory of Functions and Adjacent Problems” on Voronezh Winter Mathematical School”, Uspekhi Mat. Nauk, 55:2(332) (2000), 189–190
E. A. Asarin, I. A. Bakhtin, N. A. Bobylev, V. A. Bondarenko, V. Sh. Burd, E. A. Gorin, S. V. Emel'yanov, P. P. Zabreiko, L. A. Ivanov, V. S. Kozyakin, A. M. Krasnosel'skii, N. A. Kuznetsov, A. B. Kurzhanskii, A. Yu. Levin, È. M. Muhamadiev, A. I. Perov, Yu. V. Pokornyi, A. V. Pokrovskii, D. I. Rachinskii, V. V. Strygin, Ya. Z. Tsypkin, V. V. Chernorutski, “Memory of M. A. Krasnosel'skii”, Avtomat. i Telemekh., 1998, no. 2, 179–184
1997
61.
V. V. Gusev, Yu. V. Pokornyi, P. L. Ul'yanov, “Contemporary methods in theory of functions and adjacent problems”, Uspekhi Mat. Nauk, 52:4(316) (1997), 251–252
V. A. Il'in, S. M. Nikol'skii, Yu. V. Pokornyi, “Воронежская международная весенняя математическая школа «Понтрягинские чтения-V» (25–29 апреля 1994 г.)”, Differ. Uravn., 31:1 (1995), 178
63.
Yu. V. Pokornyi, P. L. Ul'yanov, “School “Contemporary methods in theory of functions and adjacent problems of mathematics and mechanics””, Uspekhi Mat. Nauk, 50:4(304) (1995), 187–188
V. A. Il'in, S. A. Lomov, M. S. Nikol'skii, Yu. V. Pokornyi, “«Понтрягинские чтения-IV» на весенней Воронежской математической школе”, Differ. Uravn., 30:3 (1994), 538–539
1993
65.
P. L. Ul'yanov, Yu. V. Pokornyi, “Voronezh Mathematical School “Theory of Functions, Differential Equations in Mathematical Modelling””, Uspekhi Mat. Nauk, 48:4(292) (1993), 253–254
V. A. Il'in, S. A. Lomov, Yu. V. Pokornyi, “Воронежская весенняя математическая школа «Современные методы качественной теории краевых задач»”, Differ. Uravn., 28:12 (1992), 2191
67.
V. A. Il'in, S. A. Lomov, Yu. V. Pokornyi, “Воронежская весенняя математическая школа «Современные методы качественной теории краевых задач»”, Differ. Uravn., 28:6 (1992), 1093–1094
68.
S. M. Nikol'skii, Yu. V. Pokornyi, P. L. Ul'yanov, “Voronezh Winter Mathematical School “Modern Methods in Theory of Functions and Theory of Differential Equations””, Uspekhi Mat. Nauk, 47:1(283) (1992), 227–228