Brent Lang Executive Editor When Nathan Silver’s mother was in her mid-60s, she decided to have a bat mitzvah. As the indie filmmaker started telling people that his mother was embarking on a rite of passage usually reserved for teenagers, a friend urged him to turn her story into a movie. Now, “Between the Temples,” a screwball comedy inspired by mom’s coming-of-age ceremony, will premiere at Sundance, with Carol Kane and Jason Schwartzman playing an elderly bat mitzvah student and a depressed cantor who forge an unlikely bond.