GOURSAT PROBLEM FOR THE ADJOINT MODEL TELEGRAPH EQUATION WITH THE RATE a(s,t) IN THE UPPER HALF-PLANE

Main Article Content

F. LOMOVTSEV

Abstract

In the upper half-plane, the classical solution and correctness criterion of the Goursat problem for a linear inhomogeneous adjoint model telegraph equation with variable rate a(s,t) are found explicitly. An explicit formula is obtained for the classical solution of this Goursat problem, unique and stable with respect to the right hand side of the equation and Goursat data. This formula contains implicit characteristic functions of the equation. In the case of a homogeneous conjugate model telegraph equation, the classical solution of this Goursat problem is the Riemann function in all linear mixed (initial-boundary) problems for an inhomogeneous model telegraph equation with variable rate a(s,t). This Riemann function has been calculated by us. A correctness criterion according to Hadamard (necessary and sufficient conditions) of its unique and stable on the right-hand side of the equation and the Goursat data solvability is found. This criterion consists of smoothness requirements on the righthand side of the equation and two Goursat data. The smoothness requirements on the right side of the equation are the condition of continuity of the right-side and the corresponding integral smoothness conditions on the right side of the equation and on the Goursat data – their twice continuous differentiability in the upper half-plane.

Article Details

How to Cite
LOMOVTSEV, F. (2022). GOURSAT PROBLEM FOR THE ADJOINT MODEL TELEGRAPH EQUATION WITH THE RATE a(s,t) IN THE UPPER HALF-PLANE. Vestnik of Polotsk State University. Part C. Fundamental Sciences, (4), 92-102. https://doi.org/10.52928/2070-1624-2022-38-4-92-102
Author Biography

F. LOMOVTSEV, Belarusian State University, Minsk

д-р физ.-мат. наук, проф.

References

Lomovtsev, F. E. (2021). Pervaya smeshannaya zadacha dlya obshchego telegrafnogo uravneniya s peremennymi koeffitsiyentami na polupryamoy [The first mixed problem for the general telegraph equation with variable coefficients on the half-line]. Zhurnal Belorusskogo gosudarstvennogo universiteta. Matematika. Informatika [Journal of the Belarusian State University. Mathematics and Informatics], (1), 18–38. DOI: 10.33581/2520-6508-2021-1-18-38. (In Russ., abstr. in Engl.).

Lomovtsev, F. E. (2022). Kriteriy gladkosti klassicheskogo resheniya neodnorodnogo model'nogo telegrafnogo uravneniya pri skorosti a(x,t) na poluosi [The Smoothness Criterion for the Classical Solution to Inhomogeneous Model Telegraph Equation at the Rate a(x,t) on the Half-Line]. In Trudy 10-go mezhdunarodnogo nauchnogo seminara AMADE- 2021 [Proc. 10th International Workshop AMADE-2021] (43–53). Minsk: BSU, ITC of the Ministry of Finance. (In Russ.).

Lomovtsev, F. E. (2021) Conclusion of the Smoothness Criterion for the Right-Hand Side of the Model Telegraph Equation with the Rate a(x,t) by the Correction Method. In Sovremennye metody teorii kraevykh zadach [Modern methods of the theory of boundary value problems] (284–287). Voronezh: Publ. VSU.

Schwartz, L. (1950–1951). Theorie des distributions (Vols. 1–2). Paris: Hermann.

Vladimirov, V. S. (1976). Obobshchennye funktsii v matematicheskoi fizike [Generalized functions in mathematical physics]. Moscow: Nauka. (In Russ.).

Tikhonov, A. N., & Samarskii, A. A. (2004). Uravneniya matematicheskoi fiziki [The equations of mathematical physics]. Moscow: Nauka. (In Russ.).

Lomovtsev, F. E. (2021). Riemann Formula of the Classical Solution to the First Mixed Problem for the General Telegraph Equation with Variable Coefficients on the Half-Line. Sed'mye Bogdanovskie chteniya po obyknovennym differentsial'nym uravneniyam, posvyashchennye 100-letiyu so dnya rozhdeniya professora Yu. S. Bogdanova [Seventh Bogdanov Readings on Ordinary Differential Equations, dedicated to the 100th anniversary of the birth of Professor Yu. S. Bogdanova] (201–203). Minsk: IM NAS of Belarus.

Lomovtsev, F. E., & Tochko, T. S. (2019). Smeshannaya zadacha dlya neodnorodnogo uravneniya kolebanii ogranichennoi struny pri kharakteristicheskikh nestatsionarnykh pervykh kosykh proizvodnykh na kontsakh [Mixed problem for an inhomogeneous vibration equation of a bounded string with characteristic non-stationary first oblique derivatives at the ends]. Vesnik Hrodzenskaha Dziarzhaunaha Universiteta Imia Ianki Kupaly. Seryia 2. Matematyka. Fizika. Infarmatyka, Vylichal’naia Tekhnika i Kiravanne [Vesnik of Yanka Kupala State University of Grodno. Series 2. Mathematics. Physics. Informatics, Сomputer Technology and its Сontrol], 9(2), 56–75. (In Russ.).

Lomovtsev, F. E., & Lysenko, V. V. (2019). Nekharakteristicheskaya smeshannaya zadacha dlya odnomernogo volnovogo uravneniya v pervoi chetverti ploskosti pri nestatsionarnykh granichnykh vtorykh proizvodnykh [A non-characteristic mixed problem for a one-dimensional wave equation in the first quarter of the plane with non-stationary boundary second derivatives]. Vesnіk Vіtsebskaga dzyarzhaunaga unіversіteta [Bulletin of the Vitebsk Dzyarzhaunaga University], 3(104), 5–17. (In Russ., abstr. in Engl.).