Janyarak Tongsomporn

Prof. Dr. Janyarak Tongsomporn

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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 December 2019 in Canadian Mathematical Bulletin
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JTJanyarak Tongsomporn
Janyarak Tongsomporn
JSJörn Steuding
Jörn Steuding
We prove irregularities in the distribution of prime numbers in any Beatty sequence ${\mathcal{B}}(\unicode[STIX]{x1D6FC},\unicode[STIX]{x1D6FD})$ , where $\unicode[STIX]{x1D6FC}$ is a positive real irrational number of finite type.

17 March 2026 in Symmetry
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JTJanyarak Tongsomporn
Janyarak Tongsomporn
SPSorravit Phonrakhhet
Sorravit Phonrakhhet
This work investigates the solution and the stability of a generalized system of bi-quadratic–Drygas functional equations in non-Archimedean normed spaces with unknown coefficients. The presence of asymmetric coefficients and reflection terms induces nontrivial coupling effects and symmetry-breaking phenomena, while simultaneously capturing additive, quadratic, and mixed additive–quadratic behaviors. An examination of the coefficients shows that the trivial solution is the only one satisfying the system of equations in asymmetric parameter configurations. For symmetric configurations, by exploiting the ultrametric structure of non-Archimedean norms and applying an iterative method combined with symmetry-based decomposition into even and odd parts, we establish the existence and uniqueness of an exact solution approximating a given mapping. Several known stability results for bi-Drygas functional equations are recovered with improvement as special cases.

4 October 2025 in Symmetry
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JTJanyarak Tongsomporn
Janyarak Tongsomporn
NANavin Aksornthong
Navin Aksornthong
We investigate the Hyers–Ulam–Rassias stability of a generalized quadratic functional equation of the asymmetric four-function form F(x+y)+G(x−y)=L(x)+M(y), where F, G, L, and M are unknown mappings. This study is conducted within the framework of non-Archimedean normed spaces over the p-adic numbers. Our approach employs a separation technique, analyzing the even and odd parts of the functions to establish stability results. We show that all four functions are approximated by a combination of a quadratic function and two additive functions.

16 December 2022 in Mathematics
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SWSaeree Wananiyakul
Saeree Wananiyakul
JSJörn Steuding
Jörn Steuding
JTJanyarak Tongsomporn
Janyarak Tongsomporn
We introduce a generalized adjacency matrix in order to distinguish cospectral graphs. Our reasoning is motivated by the work of Johnson and Newman and properties of p-adic numbers. Using a polynomial time algorithm, we comment on computer experiments with which we can distinguish cospectral (non-isomorphic) graphs.

15 February 2023 in Arab Journal of Basic and Applied Sciences
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SWSaeree Wananiyakul
Saeree Wananiyakul
JTJanyarak Tongsomporn
Janyarak Tongsomporn
We consider linear recursions of length two and related gap recursions where the indices may not be consecutive integers. Given a linear recursion of length two, we prove the existence of an explicit linear recursion of length l with arbitrary distance between indices. Conversely, it is shown under some mild assumption that a linear recursion of length l can be reduced to one of length two.

1 February 2023 in Mathematics
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JSJörn Steuding
Jörn Steuding
JTJanyarak Tongsomporn
Janyarak Tongsomporn
We extend Bourgain’s bound for the order of growth of the Riemann zeta function on the critical line to Lerch zeta functions. More precisely, we prove L(λ, α, 1/2 + it) ≪ t13/84+ϵ as t → ∞. For both, the Riemann zeta function as well as for the more general Lerch zeta function, it is conjectured that the right-hand side can be replaced by tϵ (which is the so-called Lindelöf hypothesis). The growth of an analytic function is closely related to the distribution of its zeros.