  Interactions between charge carriers in graphene lead to logarithmic
renormalization of observables mimicking the behavior known in
(3+1)-dimensional quantum electrodynamics (QED). Here we analyze soft
electron-hole (e-h) excitations generated as a result of fast charge dynamics,
a direct analog of the signature QED effect - multiple soft photons produced by
the QED vacuum shakeup. We show that such excitations are generated in photon
absorption, when a photogenerated high-energy e-h pair cascades down in energy
and gives rise to multiple soft e-h excitations. This fundamental process is
manifested in a double-log divergence in the emission rate of soft pairs and a
characteristic power-law divergence in their energy spectrum of the form
$\frac{1}{\omega}\ln \left(\frac{\omega}{\Delta}\right) $. Strong
carrier-carrier interactions make pair production a prominent pathway in the
photoexcitation cascade.
