Pfaffian

• pfaffian

• IPA^(key): /ˈfæfɪən/

Pfaff +‎ -ian, after Johann Friedrich Pfaff.

Pfaffian (plural Pfaffians)

1. (mathematics) The determinant of a skew-symmetric matrix, capable of being written as the square of a polynomial in the matrix entries.
   • 1993, Chris Godsil, “Pfaffians”, in Algebraic Combinatorics‎, page 113:

     If A is a skew symmetric matrix then det A is the square of a polynomial in the entries of A. This polynomial is known as the Pfaffian of A, and we denote it by Sym(pf A).

After Charles Ignatious Pfaff, the founder of the restaurant.

Pfaffian (plural Pfaffians)

1. (historical) A member of a circle of artists that met at Pfaff's, a restaurant on Broadway.
   • 1897 March 1, The Conservator‎:

     Charles E. Hurd, assistant editor of the Boston Transcript, has published in the Commercial Bulletin an academic account of the literary Bohemia of New York at the time the Pfaffians flourished and Ada Clare, Whitman's friend, reigned as its queen.

   • 1999, Ronald Lora, The Conservative Press in Eighteenth-and Nineteenth-century America‎, page 140:

     While the publication became noted for its conservatism, the Pfaffians, inspired by the writings of Henri Murger and visits to Parisian bohemian quarters, avowedly dismissed the restraints of convention and pursued a freewheeling personal lifestyle.

   • 2009, Joanna Levin, Bohemia in America, 1858–1920‎, page 70:

     SHORTLY AFTER THE PFAFFIANS announced their version of la vie bohème in the Saturday Press, the mythos of Bohemia traveled to San Francisco.