Angular momentum of zero-frequency gravitons

• By following closely Weinberg's soft theorem, which captures the 1/omega pole contribution to the amplitude for soft graviton emissions (omega < Lambda on top of an arbitrary background hard process, we calculate the expectation value of the graviton's angular momentum operator for arbitrary collisions dressed with soft radiation. We find that the result becomes independent of the cutoff Lambda on the graviton's frequency, effectively localizing at omega = 0. In this way, our result captures the contribution to the angular momentum that comes from the zero-frequency modes. Like the soft theorem, our formula has an exact dependence on the kinematics of the hard particles and is only a function of their momenta. As an example, we discuss in some detail the case of the 2 -> 2 scattering of spinless particles in General Relativity and N = 8 supergravity.

Subject headings

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Keyword

Black Holes

Classical Theories of Gravity

Scattering Amplitudes

Supergravity Models

Publication and Content Type

ref (subject category)

art (subject category)