Consistency Relations for the Conformal Mechanism

We systematically derive the consistency relations associated to the non-linearly realized symmetries of theories with spontaneously broken conformal symmetry but with a linearly-realized de Sitter subalgebra. These identities relate (N+1)-point correlation functions with a soft external Goldstone to N-point functions. These relations have direct implications for the recently proposed conformal mechanism for generating density perturbations in the early universe. We study the observational consequences, in particular a novel one-loop contribution to the four-point function, relevant for the stochastic scale-dependent bias and CMB mu-distortion.Comment: 34 pages, 3 figures. v2: minor changes, version appearing in JCA

Modeling Biased Tracers at the Field Level

In this paper we test the perturbative halo bias model at the field level. The advantage of this approach is that any analysis can be done without sample variance if the same initial conditions are used in simulations and perturbation theory calculations. We write the bias expansion in terms of modified bias operators in Eulerian space, designed such that the large bulk flows are automatically resummed and not treated perturbatively. Using these operators, the bias model accurately matches the Eulerian density of halos in N-body simulations. The mean-square model error is close to the Poisson shot noise for a wide range of halo masses and it is rather scale-independent, with scale-dependent corrections becoming relevant at the nonlinear scale. In contrast, for linear bias the mean-square model error can be higher than the Poisson prediction by factors of up to a few on large scales, and it becomes scale dependent already in the linear regime. We show that by weighting simulated halos by their mass, the mean-square error of the model can be further reduced by up to an order of magnitude, or by a factor of two when including $60\%$ mass scatter. We also test the Standard Eulerian bias model using the nonlinear matter field measured from simulations and show that it leads to a larger and more scale-dependent model error than the bias expansion based on perturbation theory. These results may be of particular relevance for cosmological inference methods that use a likelihood of the biased tracer at the field level, or for initial condition and BAO reconstruction that requires a precise estimate of the large-scale potential from the biased tracer density.Comment: 61 pages, 27 figures. Minor edits and added references to match published versio

Beyond the traditional Line-of-Sight approach of cosmological angular statistics

We present a new efficient method to compute the angular power spectra of large-scale structure observables that circumvents the numerical integration over Bessel functions, expanding on a recently proposed algorithm based on FFTlog. This new approach has better convergence properties. The method is explicitly implemented in the CLASS code for the case of number count $C_\ell$'s (including redshift-space distortions, weak lensing, and all other relativistic corrections) and cosmic shear $C_\ell$'s. In both cases our approach speeds up the calculation of the exact $C_\ell$'s (without the Limber approximation) by a factor of order 400 at a fixed precision target of 0.1%.Comment: 40 pages, 6 figures; v2: one reference adde

The emergence of postcyclic prosody in loanword integration: Toneless Latinate adjectives in Serbo-Croatian

A case of exceptional assignment of prosody to loanwords is considered. In Serbo-Croatian, where in loanwords the original position of stress is generally preserved in some way, a small class of Latinate adjectives (e.g., "elementārna ‘elementary’ and p"ersonālna ‘personal’) become toneless and they display the postcyclic initial falling accent. An account of these data is proposed which combines a new approach to postcyclic prosody, which is shown to go hand in hand with syntactically opaque structures, and a new model of loanword integration, which views the loanword trajectory as lexicalisation. As a result, an enriched theory of both domains and their interaction arises to account for the data and shed some additional light on the position of loanwords in the architecture of the grammar/lexicon