A general multipoint boundary value problem for non-uniformly $2b$-parabolic equations with degeneration is studied. The coefficients of the parabolic equations and boundary conditions admit power degeneracy of arbitrary order in the time variable and the spatial variables on a certain set of points. To solve the posed multipoint boundary value problem, solutions of problems with smooth coefficients in Hölder spaces with the corresponding norm are studied. Using interpolation inequalities and a priori estimates, estimates of the solution of auxiliary problems and their derivatives in special Hölder spaces are established. Using the Riesz and Archel theorems, a convergent sequence is distinguished from the compact sequence of solutions of auxiliary problems, the limiting value of which is the solution of a multipoint time boundary value problem for a $2b$-parabolic equation with degeneration. The estimates of the solution of the posed problem are established in Hölder spaces with power-weight. The order of the power-weight is determined by the order of singularities of the coefficients of the equations and boundary conditions. With certain restrictions on the right-hand side of the equation and boundary conditions, an integral representation of the posed problem is obtained.
[1] Ptashnyk B. Y., Il’kiv V. S., Kmit’ I. Y., Polishchuk V. M. Nonlocal boundary value problems for equations with partial derivatives. Kyiv : Scientific thought, 2002. 416 p.
[2] Ptashnyk B. Y., Tymkiv I. R. A multipoint problem for a parabolic equation with variable coefficients. Reports of the National Academy of Sciences of Ukraine. 2008. № 12. P. 42-48.
[3] Klyus I. S., Ptashnyk B. Y. A multipoint problem for equations with partial derivatives that are not solvable with respect to the highest time derivative. Ukrainian Mathematical Journal 1999. 51, № 12. P. 1604-1613.
[4] Matiychuk M. I. Parabolic and elliptic boundary value problems with singularities. Chernivtsi : Prut, 2003. 248 p.
[5] Pukal’skii I.D., Yashan B.O. A boundary value problem with impulse action for a parabolic equation with degeneration. Ukrainian Mathematical Journal 2019. 71, № 5. P. 645-655.
[6] Pukal’skii I.D., Yashan B.O. A nonlocal multipoint time problem for parabolic equations with degeneration. Mathematical methods and physical and mechanical fields, 2017. 60, № 2. P. 32-40.
[7] Pukal’skii I.D. The Cauchy problem for non-uniformly parabolic equations with power singularities. Mathematical methods and physical and mechanical fields, 2021. 64, № 2. P. 31-41.
[8] PukalskyyI.D.,YashanB.O. A multipoint in-time problem for the 2b-parabolic equation with degeneration. Bukovinian Math. Journal. 10, №2 (2022), 229-239.
[9] Friedman A. Partial differential equations of paraboloc type. Englewood Clifts; Prentice Hall, 1964. 347 р.
[10] Matiychuk M. I. Parabolic singular boundary value problems. Kyiv : Institute of Mathematics of the National Academy of Sciences of Ukraine, 1999. 176 p.
[11] Agmon S., Douglas A., Nirenberg L. Estimates noar the boundary of solutions of elliptic equations in partial derivatives under common boundary conditions. M.: JL, 1962. 205 р.
- ACS Style
- Pukalskyi, I.; Yashan, B.O. A multipoint boundary value problem in time for a 2b-parabolic equation with degeneracy. Bukovinian Mathematical Journal. 2024, 12 https://doi.org/ https://doi.org/10.31861/bmj2024.01.09
- AMA Style
- Pukalskyi I, Yashan BO. A multipoint boundary value problem in time for a 2b-parabolic equation with degeneracy. Bukovinian Mathematical Journal. 2024; 12(1). https://doi.org/ https://doi.org/10.31861/bmj2024.01.09
- Chicago/Turabian Style
- Ivan Pukalskyi, Bohdan Olehovych Yashan. 2024. "A multipoint boundary value problem in time for a 2b-parabolic equation with degeneracy". Bukovinian Mathematical Journal. 12 no. 1. https://doi.org/ https://doi.org/10.31861/bmj2024.01.09