“…Since 2000, O. G. Smolyanov and members of his group succeeded in representing solutions of the Cauchy problem for many evolution equations in form of Feynman formulas (see [39,40,41,42,43,47,48,49,51,52,48,54,61,57,58,44] and refereces therein). The key idea in these representations lies in finding the Chernoff function G for operator L and then applying Chernoff's theorem to obtain the equality e tL u 0 = lim n→∞ G(t/n) n u 0 which apperas to be a Feynman formula, because in all known examples (until [50] was published in 2016, see also [44,63]) G(t) from the equation above was an integral operator, so G(t/n) n was an n-tuple integral operator, giving us a limit of multiple integral where miltiplicity tends to infinity.…”