BVP Symmetry

Notwithstanding Covid-19 pandemic is over, Notwithstanding Covid-19 pandemic is over, my recent paper is devoted to new mathematical model that takes into account the well-knonw observation that death rate and morbidity rate depend essentially on age of humans. Actually, the model is a generalisation of that I created in 2020. Of course, this paper is mostly theoretical, however, I hope that one can be useful for estimation and prediction of numbers of infected persons and deaths caused by the pandemic in specific countries.
https://doi.org/10.1007/s12346-025-01340-9 At least, the previous model (see Refs. 5 and 7) was successfully applied for these purposes in some countries including Ukraine.

An Age-Structured Diffusive Model for Epidemic Modelling: Lie Symmetries and Exact Solutions - Qualitative Theory of Dynamical Systems A new age-structured diffusive model for the mathematical modelling of epidemics is suggested. The model can be considered as a generalization of two models suggested earlier for similar purposes. The Lie symmetry classification of the model is derived. It is shown that the model admits an infinite-...

Georgy Voronoi (Heorhiy Voronyi in the Ukrainian transliteration) is the most fameous Ukrainian mathematician of the period the end of the 19th century --the beginning of the 20th c. His brilliant papers are still cited although they were published 100+ years ago.

For example, very recently his work published in French (in the beginning of 1900s English was NOT a main language for scientific publications)

Voronoi, G. Nouvelles applications des paramètres continus à la théorie des formes quadratiques. Deuxième mémoire. Recherches sur les paralléloèdres primitifs. Reine Angew. Math. 1908, 134, 198–287.

is cited in Mathematics 2024, 12(15), 2426; https://doi.org/10.3390/math12152426

There is a short article devoted to Voronyi in the English Wiki https://en.wikipedia.org/wiki/Georgy_Voronoy
(of course, his detailed biography can be found in Ukrainian).
See also the books
Voronoï's Impact on Modern Science (1998). Volumes 1,2
that were published in English thanking efforts of Dr. Halyna Syta

Georgy Voronoy - Wikipedia Georgy Feodosevich Voronyi (Russian: Георгий Феодосьевич Вороной; Ukrainian: Георгій Феодосійович Вороний; 28 April 1868 – 20 November 1908) was an Imperial Russian mathematician of Ukrainian descent noted for defining the Voronoi diagram.[1][2]