Our Dark Sector group at JPL has recently started an initiative to expand our skillsets towards deep learning, eventually coming up with new ideas to tackle the challenges that we'll face in the current and upcoming generation of cosmological surveys. I've thus started to dig into the deep learning book by Francois Chollet, which I … Continue reading Looking more into deep learning and missing power on large scales

## Filtering and re-gridding large scale HI data

Tom Kuiper (JPL) presented a project to fully automate radio astronomy in the Deep Space Network (DSN). The main purpose of the DSN is to communicate with all the NASA spacecrafts, but there is plenty of idle time in which the 34m and 70m dishes could be used for radio astronomy. We'll soon have the … Continue reading Filtering and re-gridding large scale HI data

## CMB foregrounds in San Diego

We had a CMB foregrounds workshop just last week at UCSD, coming together to develop a plan for the next year until the CMB Probe Mission Study will be submitted. Our main goal will be to demonstrate that we can control the component separation to a degree that allows us to obtain competitive constraints on the … Continue reading CMB foregrounds in San Diego

## First look into the scale-dependent bias and non-Gaussianity

This afternoon, I worked on a model implementation of the scale-dependent bias, following the ansatz of De Putter & Doré (2014, their Eq. 1). The goal is to constrain the fNL parameter which quantifies the amplitude of the primordial non-Gaussianity. These primordial density fluctuations are very Gaussian, but a small departure from this Gaussianity or limits on … Continue reading First look into the scale-dependent bias and non-Gaussianity

## Python packaging, astropy, and Travis CI

Last week, I started to re-visited quickspeck, a python package by Duncan Hanson that allows to create angular power spectra for cosmic fields under the Limber approximation (see this paper for a nice overview and an extension). In light of the upcoming CMB lensing workshop at Stanford and our ongoing work on the cross correlation between … Continue reading Python packaging, astropy, and Travis CI

## Power spectra of Planck CMB lensing maps

I have recently been working on the cross-correlation of CIB intensity and CMB lensing from the Planck data. I've had a few hiccups with the format of the lensing data and thus decided to document this properly in a notebook, just in case others ran into similar issues. The notebook with the calculations and examples … Continue reading Power spectra of Planck CMB lensing maps

## The final take on angular power spectra in HEALPix?

I've been working on the problem of computed the angular power spectrum for quite some time now, and nothing quite satisfied my needs. The problem is as follows: For a given map in the HEALPix format (Gorski+ 2005), the angular power spectrum of a map (or the cross power between two maps) needs to be … Continue reading The final take on angular power spectra in HEALPix?