THE UNBEARABLE LIGHTNESS OF FASHION: Forever 21 is bringing its hologram fashion show to the U.S. The runway show, which replaced live models with holograms, launched in Vienna in May before traveling to Brussels and London. The show Thursday will take place at The Grove in Los Angeles and at the Daryl Roth Theatre in Manhattan’s Union Square on Oct. 25. Produced in conjunction with space150, a digital agency, the seven-minute fashion show features holographic models walking a cosmic runway and disappearing into starbursts and climbing invisible staircases. Forever 21 will open its first ever pop up shop at each event site with looks from the fashion show. Forever 21 has used cutting edge technology before. In June 2010, the retailer used an interactive billboard in Times Square that featured onscreen models who interacted with people outside of the store by “picking up” the people and dropping them into a store shopping bag.