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OPTIMAL APPROXIMATION BY ONE GAUSSIAN FUNCTION TO PROBABILITY DENSITY FUNCTIONS

  • Gwang Il Kim (Department of Mathematics, Gyeongsang National University) ;
  • Seung Yeon Cho (Department of Mathematics, Gyeongsang National University) ;
  • Doobae Jun (Department of Mathematics, Gyeongsang National University)
  • Received : 2023.08.04
  • Accepted : 2023.09.30
  • Published : 2023.09.30

Abstract

In this paper, we introduce the optimal approximation by a Gaussian function for a probability density function. We show that the approximation can be obtained by solving a non-linear system of parameters of Gaussian function. Then, to understand the non-normality of the empirical distributions observed in financial markets, we consider the nearly Gaussian function that consists of an optimally approximated Gaussian function and a small periodically oscillating density function. We show that, depending on the parameters of the oscillation, the nearly Gaussian functions can have fairly thick heavy tails.

Keywords

Acknowledgement

This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government(MSIT) (No. NRF-2021R1I1A3048350, RS-2022-00166144, NRF-2021R1A2C1014001).

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