This week in SundayArts News: “Julie Mehretu: Grey Area” through October 6 at the Guggenheim, Summer on the Hudson:  “Acoustic Sundays” through August 15 and “Children’s Performance Series” through August 12, SummerStage: “The Dance of Light” on July 17 at Queensbridge Park, Queens, Lincoln Center Festival: “Teorema” (July 15, 16, 17, 18, 19) and “A Disappearing Number” (July 15, 16, 17 and 18), “The Glory of Ukraine: Sacred Images from the 11th to the 19th Centuries” at the Museum of Biblical Art through September 12.