Primordial Non-Gaussianities and Zero-Bias Tracers of the Large-Scale Structure

Area of Science:

• Cosmology
• Large-Scale Structure Formation
• Statistical Analysis

Background:

• Primordial non-Gaussianities provide crucial insights into the early universe.
• Current methods for constraining local primordial non-Gaussianities (fNLloc) face limitations in precision.
• Large-scale structure (LSS) tracers are essential for probing cosmological parameters.

Purpose of the Study:

• To develop a novel method for constraining local primordial non-Gaussianities.
• To investigate the effectiveness of unclustered tracers for improving precision.
• To propose a practical technique for constructing optimal tracers.

Main Methods:

• Utilizing unclustered tracers of the large-scale structure.
• Developing a method to construct tracers using environmental information.
• Validating the technique with N-body simulations.

Main Results:

• Unclustered, zero-bias tracers offer significant improvements over standard methods.
• The primary advantage stems from the vanishing of sampling variance.
• The proposed method demonstrates the potential to reach σ_{f_{NL}^{loc}}≃1.

Conclusions:

• A new, effective method for constraining local primordial non-Gaussianities has been developed.
• Unclustered tracers are a powerful tool for enhancing precision in cosmological measurements.
• The technique is robust and validated by simulations, paving the way for future studies.