Constraining primordial and gravitational mode coupling with the position-dependent bispectrum of the large-scale structure

Understand

We develop and study the position-dependent bispectrum.

• It is a generalization of the recently proposed position-dependent power spectrum method of measuring the squeezed-limit bispectrum.
• The position-dependent bispectrum can similarly be used to measure the squeezed-limit trispectrum in which one of the wavelengths is much longer than the other three.
• In this work, we will mainly consider the case in which the three smaller wavelengths are nearly the same (the equilateral configuration).