Six-dimensional spinors in NLO amplitudes and a new approach to the complex universe

Abstract: part I Part I of this thesis explores a numerical, six-dimensional spinor helicity approach to next-to-leading-order (NLO) virtual amplitude calculations for the gluon fusion production of a Higgs boson, scalable for high-multiplicity jets. Abstract: part II The standard cosmological model has achieved the status of a concordance model, but remains incomplete and subject to increasing challenge. Part II of this thesis is an exposition of an alternative approach, that acknowledges the universe as a complex system. The new theoretical framework I suggest puts complexity centre-stage by incorporating the self-organised criticality (SOC) paradigm first proposed by Bak, Tang and Wiesenfeld and releasing GR from the FLRW constraints into which it has historically been squeezed. This SOCGR framework predicts observed phenomena without the necessity of unknown matter or energy and supports further scientific investigation.