  We consider the Ising model on the Bethe lattice with aperiodic modulation of
the couplings, which has been studied numerically in Phys. Rev. E 77, 041113
(2008). Here we present a relevance-irrelevance criterion and solve the
critical behavior exactly for marginal aperiodic sequences. We present
analytical formulae for the continuously varying critical exponents and discuss
a relationship with the (surface) critical behavior of the aperiodic quantum
Ising chain.
