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Integro-differential equations and functional analysis
On real roots of systems of trancendental equations with real coefficients
A. M. Kytmanov, O. V. Khodos Siberian Federal University, Krasnoyarsk, Russian Federation
Abstract:
The work is devoted to the study of the number of real roots of systems of transcendental equations in $\mathbb C^n$ with real coefficients, consisting of entire functions, in some bounded multidimensional domain $D\subset \mathbb R^n$. It is assumed that the number of roots of the system is discrete (then it is no more than countable). For some entire function $\varphi (z), z\in \mathbb C^n$, with real Taylor coefficients at $z=0$, and a given system of equations, the concept of a resultant $R_\varphi(t)$ is introduced, which is an entire function of one complex variable $t$. It is constructed using power sums of the roots of the system in a negative degree, found using residue integrals. If the resultant has no multiple zeros, then it is shown that the number of real roots of the system in $D=\{x\in \mathbb R^n: a<\varphi(x)<b\}$ ($x=\mathrm{Re}\, z $) is equal to the number of real zeros of this resultant in the interval $(a,b)$. An example is given for a system of equations.
Keywords:
systems of transcendental equations, resultant, simple roots.
Received: 29.02.2024 Revised: 25.04.2024 Accepted: 06.05.2024
Citation:
A. M. Kytmanov, O. V. Khodos, “On real roots of systems of trancendental equations with real coefficients”, Bulletin of Irkutsk State University. Series Mathematics, 49 (2024), 90–104
Linking options:
https://www.mathnet.ru/eng/iigum577 https://www.mathnet.ru/eng/iigum/v49/p90
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