Vivian Mercier, 70, an Irish literary critic and academic whose published works include a major study on the work of Samuel Beckett. Mercier taught at New York University, the University of Colorado at Boulder and UC Santa Barbara. His published works included "The Irish Comic Tradition," "A Reader's Guide to the French New Novel" and "Samuel Beckett." The last book was done with the cooperation of the reclusive author, an Irishman who has long lived in France. Mercier, born Herbert Samuel Mercier, attended Trinity College in Dublin where Beckett had studied earlier. It was while he was a student there that he first became interested in Beckett, although he did not write the biography until the early 1970s. Mercier was also co-editor of an anthology, "A Thousand Years of Irish Prose," and was at work on a "A New Critical History of Anglo-Irish Literature." In London on Saturday of undisclosed causes.