Ayarna, a first-team All-American, had one year of eligibility remaining. He recently played in the U.S. Open Cup for Boston Olympiacos.
The 6-foot-3 Campos, who had one year of eligibility left at Fresno Pacific, had attracted considerable interest from MLS's Real Salt Lake. He leads the PDL with 14 goals in 10 games.
GAIS is 10th in the 16-team Allsvenskan as the midseason approaches. It has scored only 12 goals in 13 games.
Ayarna joins former BC teammate Charlie Davies in Sweden. Davies also left the Eagles early, signing with Hammarby in 2007.
"Pablo has size and speed, and he's ready to go," Fresno Pacific coach Jaime Ramirez told the Fresno Bee. "I'm sure [the Swedish team] saw the video against Chivas USA, where he was able to hold off a defender as good as Claudio Suarez, and said, 'We need to look at this guy.'"
Campos, a transfer from Oklahoma Baptist, was one of three Brazilians on FPU's roster in 2007.