Color-Kinematics Duality and Gravitational Waves

• Recent developments in theoretical physics have led to new insights for gauge theory and gravity scattering amplitudes.The color-kinematics duality, in particular, describes an intriguing set of identities obeyed by the kinematic numerators of gauge-theory scattering amplitudes, mirroring the Jacobi identity of the color factors.  The kinematic Jacobi identities suggest the existence of some unknown kinematic algebra underlying the gauge-theory Feynman rules. However, as of yet, there is no complete Lagrangian construction of duality-satisfying numerators, nor an off-shell realization of a kinematic algebra even for pure Yang-Mills gauge theory. This thesis presents substantial progress on these open problems, first through a Lagrangian whose Feynman rules compute duality-satisfying numerators in the NMHV sector of Yang-Mills theory. In addition, Chern-Simons gauge theory is shown to obey the color-kinematics duality completely off shell, giving rise to a kinematic algebra of volume preserving diffeomorphisms. Similar structures are also identified in the pure-spinor description of super Yang-Mills theory.The recent detection of gravitational waves by the LIGO/Virgo/KAGRA collaboration, as well as anticipated improvement in sensitivity of future detectors, call for improved precision of the theoretical predictions for binary merger events. Analytical computations involving gravitating and rotating compact objects require both increased classical loop orders in the gravitational coupling as well as the incorporation of spin effects, which have important contributions to the dynamics. For this purpose, an extension of the worldline quantum field theory is presented, based on the effective worldline action of a classical spinning compact object. The formalism is used to compute tree and one-loop amplitudes up to fourth order in spin, and coefficients in the effective worldline action are fixed such that it reproduces known Kerr observables from black hole perturbation theory.

Ämnesord

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

NATURAL SCIENCES  -- Physical Sciences -- Other Physics Topics (hsv//eng)

Nyckelord

Quantum field theory

gravitational waves

scattering amplitudes

Theoretical Philosophy

Teoretisk filosofi

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