Published online by Cambridge University Press: 20 March 2017
Given an L–space knot we show that its ϒ function is the Legendre transform of a counting function equivalent to the d–invariants of its large surgeries. The unknotting obstruction obtained for the ϒ function is, in the case of L–space knots, contained in the d–invariants of large surgeries. Generalisations apply for connected sums of L–space knots, which imply that the slice obstruction provided by ϒ on the subgroup of concordance generated by L–space knots is no finer than that provided by the d–invariants.