Gwyneth ("Sliding Doors," "Shakespeare in Love") Paltrow becomes the latest in a string of American film stars to make her London stage debut, in Proof, at the Donmar on May 15. She will be doing so in another smart American play (like Kenneth Lonnergan's Lobby Hero, which preceded it), for Proof has already won author David Auburn the 2001 Pulitzer Prize and a Tony.

Directed by John Madden (who also directed her in "Shakespeare in Love"), Paltrow plays the daughter of a mathematical genius who fears she may have inherited his mental illness as well as his skill at math.

The entire run of the play sold out shortly after booking opened, though there are some standing seats available for every evening performance, from 10 AM on the day, in person, at the box office.

There hasn't been so much press attention to one of the Donmar's leading ladies since Nicole Kidman appeared (with Ian Glen) in The Blue Room. There is an unspoken rivalry between Miss Paltrow (or her supporters, at any rate) and Madonna — who opens at Wyndham's in Up For Grabs on May 25. Which of the two will be the American Queen of the West End?