As winter’s first snowflakes floated down over the theater district, two actors and their director were discussing the fine points of physics (theoretical) and kissing (actual). Playing a scientist and a beekeeper at the beginning of what might be a romance, Ruth Wilson and Jake Gyllenhaal experimented with different tones — brusque, tentative, flirtatious — and degrees of drunkenness. “Make sure you’re someone who could be slept with,” the director, Michael Longhurst, told Mr. Gyllenhaal.

Ms. Wilson, rehearsing for her Broadway debut in the two-character play “Constellations” just a few months after filming her first American television series, “The Affair,” held a finger to her lips and stared at the floor, considering the options.

“Shall we try it again?” she said, adding, with an inscrutable mix of apology and annoyance, “It’s a lot of kissing.”

“Constellations,” a short, complex drama by the young playwright Nick Payne, has made the move from London to Broadway partly because of the Hollywood star power of Mr. Gyllenhaal, who, as the bearded, ardent beekeeper, is definitely someone who could be slept with. But Ms. Wilson, with her offhand intensity and overscale features — dramatically wide lips, piercing blue-gray eyes, architectural eyebrows — was more than holding her own in the rehearsal studio.