How did Thor return to Earth in The Avengers?

In Thor, it's stated that the Bifrost Bridge is how Asgardians travel between the worlds. When Thor destroys the Bridge at the end of his first film, Loki and Thor have the following exchange.

LOKI: Stop! What are you doing?! If you destroy the Bridge, you'll never see her again!

THOR: Forgive me.

^{Thor transcript via The Internet Movie Script Database}

If the bridge was destroyed, how does Thor return to Earth in The Avengers? Is there any in-universe explanation?

Best Answer

LOKI: Oh, you should thank me. With the Bifrost gone how much dark energy did the Allfather have to muster to conjure you here? Your precious Earth.

^{The Avengers transcript via The Internet Movie Script Database}

While it's never explicitly explained in The Avengers how Thor returned to Earth, Loki implies that Odin used dark energy to send him back.

This is confirmed in the prelude comic for Thor: The Dark World, where Odin uses dark magic to send Thor to Earth/Midguard after seeing that Loki was planning on stealing the Tesseract.

According to alexwlchan on Science Fiction and Fantasy, in second issue of the same comic, Thor and Heimdall use the power of the Tesseract to rebuild the Bifrost Bridge.

We see this newly rebuilt bridge in Thor: The Dark World, which is presumably how Thor returns to Earth in each subsequent movie after The Avengers.