@article { , title = {The covariance of multi-field perturbations, pseudo-susy and fNL}, abstract = {We reconsider cosmological perturbation theory for multi-component scalars, enforcing covariance in field-space, and ensuring that phyical observations are independent of field re-definitions. We use the formalism to clarify some issues in the literature, and use pseudo-supersymmetry to derive exact expressions for terms of interest.}, doi = {10.1088/1475-7516/2012/09/002}, eissn = {1475-7516}, issue = {9}, journal = {Journal of Cosmology and Astroparticle Physics}, publicationstatus = {Published}, publisher = {IOP Publishing}, url = {https://nottingham-repository.worktribe.com/output/711548}, volume = {2012}, keyword = {Cosmological perturbation theory}, year = {2012}, author = {Saffin, Paul M.} }