I was browsing through the hep-th arXiv and came across this article:

Spontaneous Lorentz Violation in Gauge Theories. A. P. Balachandran, S. Vaidya. arXiv:1302.3406 [hep-th]. (Submitted on 14 Feb 2013)

The authors say that Lorentz symmetry is spontaneously broken in QED and also in non-abelian gauge theories by infrared effects. However as far as I know the observed world is Lorentz invariant. Can someone kindly explain to me what is going on? Thanks for any help!