Neutrino non-standard interactions (NSI) with electrons are known to alter the picture of neutrino decoupling from the cosmic plasma. NSI modify both flavour oscillations through matter effects, and the annihilation and scattering between neutrinos and electrons and positrons in the thermal plasma. In view of the forthcoming cosmological observations, we perform a precision study of the impact of non-universal and flavour-changing NSI on the effective number of neutrinos, $N_{\mathrm{eff}}$. We present the variation of $N_{\mathrm{eff}}$ arising from the different NSI parameters and discuss the existing degeneracies among them, from cosmology alone and in relation to the current bounds from terrestrial experiments. Even though cosmology is generally less sensitive to NSI than these experiments, we find that future cosmological data would provide competitive and complementary constraints for some of the couplings and their combinations.

已知中微子与电子的非标准相互作用 (NSI) 会改变中微子与宇宙等离子体解耦的图像。NSI 通过物质效应以及热等离子体中中微子与电子和正电子之间的湮灭和散射来修改风味振荡。鉴于即将进行的宇宙学观测，我们对非普遍性和风味变化的 NSI 对中微子有效数量的影响进行了精确研究，$N_{\mathrm{效果}}$. 我们提出了$N_{\mathrm{效果}}$由不同的 NSI 参数引起，并讨论它们之间现有的简并性，仅从宇宙学和与地球实验的当前界限有关。尽管宇宙学对 NSI 的敏感性通常低于这些实验，但我们发现未来的宇宙学数据将为某些耦合及其组合提供竞争性和互补性约束。