Loop gravity---two questions A poster in another thread writes: A question: Then the SO(2) connection used like a variable in Ashtekar's general relativity is a real connection or a complex connection? There are papers that say that is real and others that is complex.... I've just read that loop quantum gravity violates the "weak energy condition" at short distances, when the granularity of spacetime becomes significant. I've don't have the foggiest idea of what is the weak energy condition... -------------------------- Comments invited. My understanding is that Ashtekar's new variables for GR initially involved a complex connection and that physical solutions required imposing some additional conditions called "reality conditions". The original suggestion for making the connection real from the start came, i believe, from Barbero and involved an undetermined (real number) parameter called the Barbero-Immirzi parameter. I dont recall hearing about a "weak energy condition" that loop gravity fails to satisfy. Anyone who can step in to shed addtional light on either of these two questions (from Meteor) is most cordially welcome. Meteor, I'm trying to use that other thread as a sticky in which to collect useful links and general information, conferences etc., source material. Let's start a thread here with your questions in case they lead to discussion.