Who was Alfred Jensen (1903–81)? A geometric abstractionist, you say? But his trademark grids of tiny, brightly colored triangles and squares are so heavily impastoed that, from ten feet away, the geometry wiggles like a desert horizon. An atelier mystic, à la Mark Tobey or Morris Graves? Hardly: The “esoterica” on which Jensen draws includes math and physics as well as Chinese and Mayan calendrical systems. Perhaps Dia’s season-long dozen-painting exhibition—which includes the never-before-publicly-exhibited Great Pyramid, 1979, a twelve-panel masterpiece considered the artist’s last major statement— will provide an answer.

— Peter Plagens