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arXiv · 1909.04022

The EFT Likelihood for Large-Scale Structure

Giovanni Cabass·Fabian Schmidt
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Abstract

We derive, using functional methods and the bias expansion, the conditional likelihood for observing a specific tracer field given an underlying matter field. This likelihood is necessary for Bayesian-inference methods. If we neglect all stochastic terms apart from the ones appearing in the auto two-point function of tracers, we recover the result of Schmidt et al., 2018. We then rigorously derive the corrections to this result, such as those coming from a non-Gaussian stochasticity (which include the stochastic corrections to the tracer bispectrum) and higher-derivative terms. We discuss how these corrections can affect current applications of Bayesian inference. We comment on possible extensions to our result, with a particular eye towards primordial non-Gaussianity. This work puts on solid theoretical grounds the EFT-based approach to Bayesian forward modeling.

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Giovanni Cabass, Fabian Schmidt. 2019-09-09. The EFT Likelihood for Large-Scale Structure. https://doi.org/10.1088/1475-7516/2020/04/042

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