text: ---
  abstract: 'The method of weighted addition of multi-frequency maps, more commonly referred to as [*Internal Linear Combination*]{} (ILC), has been extensively employed in the measurement of cosmic microwave background (CMB) anisotropies and its secondaries along with similar application in 21cm data analysis. The performance of the simple ILC method is, however, limited, but can be significantly improved by adding constraints informed by physics and existing empirical information. In recent work, a moment description has been introduced as a technique of carrying out high precision modeling of foregrounds in the presence of inevitable averaging effects. We combine these two approaches to construct a heavily constrained form of the ILC, dubbed [[MILC]{}]{}, which can be used to recover tiny spectral distortion signals in the presence of realistic foregrounds and instrumental noise. This is a first demonstration for measurements of the monopolar and anisotropic spectral distortion signals using ILC and extended moment methods. We also show that CMB anisotropy measurements can be improved, reducing foreground biases and signal uncertainties when using the [[MILC]{}]{}. While here we focus on CMB spectral distortions, the scope extends to the 21cm monopole signal and $B$-mode analysis. We briefly discuss augmentations that need further study to reach the full potential of the method.'
  author:
  - |
      Aditya Rotti[^1] and Jens Chluba[^2]\
      Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, U.K.
  bibliography:
  - 'Lit.bib'
  - 'Lit1.bib'
  - 'mendeley\_cmb.bib'
  ---
  
  Cosmology - cosmic microwave background; Cosmology - observations and foreground; Cosmology - theory and analysis methods;
  
  [^1]: E-mail:aditya.rotti@manchester.ac.uk
  
  [^2]: E-mail:jens.chluba@manchester.ac.uk
  