Improving constraints on baryon acoustic oscillations with field-level inference

We present results of field-level inference of the baryon acoustic oscillation (BAO) scale <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:msub> <a:mi>r</a:mi> <a:mi>s</a:mi> </a:msub> </a:math> on rest-frame dark matter halo catalogs. Our field-level constraint on <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:msub> <c:mi>r</c:mi> <c:mi>s</c:mi> </c:msub> </c:math> is obtained by explicitly sampling the initial conditions along with the bias and noise parameters via the LEFTfield EFT-based forward model. Comparing with a standard reconstruction pipeline applied to the same data and over the same scales, the field-level constraint on the BAO scale improves by a factor of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mrow> <e:mo>∼</e:mo> <e:mn>1.2</e:mn> <e:mi>–</e:mi> <e:mn>1.4</e:mn> </e:mrow> </e:math> over standard BAO reconstruction. We point to a surprisingly simple source of additional information.