ON FINITE GROUPS ISOSPECTRAL TO THE SIMPLE GROUP S4(3)

The spectrum of a finite group is the set of its element orders. A finite group G is called critical with respect to a subset omega of natural numbers if omega coincides with the spectrum of G and does not coincide with the spectra of proper sections of G. We study the structure of finite groups with the same spectrum as the simple symplectic group PSp(4, 3). In particular, we describe groups critical with respect to the spectrum of PSp(4, 3)