in answer to your excess of tags, lol:
no, as far as it's been written, time doesn't move differently in asgard
the span of time between the movies thor and the avengers is only meant to be a one-to-two year gap, but loki didn't age any more than thor did in that time
the reason loki looks a lot older in the avengers is because he's been stressed to the breaking point. after he tried to kill odin and thor, and tried to rein over asgard and then lol failed, his exile didn't treat him well
he was living and working amongst chitauri warmongers, kissing ass and brown nosing his way into being presented with an army- that was the deal with the tesseract. he's not actually older, he's just worn the fuck out
I see! That makes sense, even if it is much less fun to think about. I can see how even a couple years in exile could wear on a guy, particularly one with as much baggage as Loki. The whole bit about Loki sulking while Thor comes to terms could still stand, though, in a much more interesting way; he does still refer to the war as having been 'in his youth', implying that he's mentally aged a good bit since then. A couple years, in the life of a race who lives several dozen thousands of years, is just a blink of an eye--and while Loki is still at relatively the same place, emotionally and mentally, as he was at the beginning of his exile, Thor has taken some mighty character steps. He's forgiven his brother for trying to kill his father, trying to kill Thor, taking over Asgard, and the myriad other instances of assholery involved in that whole situation. He mourned him, accepted that his brother was dead, dealt with the sudden revelation that his brother was actually alive (and still a prick), and then was willing to welcome him home despite everything.
Aaaaaaaaahhhhhhh too many feels, cannot deal, I'm going to go do History work or something instead
