“Imprints for a Fleeting Memorial,” an exhibition of installations, videos, and works on paper by the Colombian artist Oscar Muñoz, haunts the viewer with images that evaporate, disintegrate, or in some other way vanish before our eyes. These ingenious portraits and self-portraits, rendered in a variety of formats, emphasize the fluidity and instability of the self, showing it to be a never-solid, ever-dissolving entity that requires constant management in order to appear whole. It’s a figuration of self-erosion that speaks to the universal human problems of aging, decay, and death while expanding