Original paper (free): <a href="http://prx.aps.org/pdf/PRX/v2/i3/e031018" rel="nofollow">http://prx.aps.org/pdf/PRX/v2/i3/e031018</a><p>A talk by the authors: <a href="http://www.weizmann.ac.il/complex/tlusty/talks/Loops2012.pdf" rel="nofollow">http://www.weizmann.ac.il/complex/tlusty/talks/Loops2012.pdf</a><p>Some discussions in forums suggest some possible relation with other self-referential constructs in math such as recursive functions, logical paradoxes, Godel incompleteness, etc.