Abstract:
4-point conformal block plays an important part in the analysis of the conformal
invariant operator algebra in two-dimensional space. Asymptotics of the conformal block
is calculated in the limit when the dimension $\Delta$ of the intermediate operator tends to
infinity. This makes it possible to construct a recurrent relationship for this function
connecting the conformal block with arbitrary $\Delta$ with the blocks corresponding to the
dimensions of zero vectors in degenerate representations of Virasoro algebra. This relationship
is useful for calculating the conformal block expansion in powers of the uniformizing
parameter $q=\mathrm{exp}\,i \pi\tau$.