act_dr6_lite
================================================

Foreground-marginalised primary CMB (CMB-only) from ACT DR6 data.

+-------------+---------------------------------------------------+
| File        | likelihood/act-dr6-lite/act_dr6_lite_interface.py |
+-------------+---------------------------------------------------+
| Attribution | Hidde T. Jense, ACT Collaboration (Library)       |
+-------------+---------------------------------------------------+
|             | Ian Harrison, CosmoSIS Team (Interface)           |
+-------------+---------------------------------------------------+
| URL         | https://github.com/ACTCollaboration/DR6-ACT-lite  |
+-------------+---------------------------------------------------+
| Citations   | https://arxiv.org/abs/2503.14452                  |
+-------------+---------------------------------------------------+

Important note: please see https://github.com/ACTCollaboration/ACT-DR6-parameters/blob/main/theories/camb.yaml
for the default CAMB settings required for this likelihood to reproduce the published result. This also requires
the use of the CosmoRec recombination module which is not supplied by default in CAMB. This repo also specifies 
default priors for the likelihood, including the tau prior which should be used if no large scale CMB polarisation 
data (e.g. from Planck SRoll2) is included.

This is the `lite` or CMB-only likelihood from the ACT DR6 data release. This marglinalises all foreground
and calibration parameters for ACT DR6 CMB TT TE and EE spectra into a single overall calibration parameter 
and a single polarisation efficiency parameter. For Lambda-CDM (and Lambda-CDM ONLY) this has been shown to 
reproduce results from the full multi-frequency likelihood to within signficantly less than 0.1sigma.
What is supplied here is only the CosmoSIS interface to the official Cobaya likelihood.
This should be obtainable through installing the Cobaya likelihood from the provided github repository.
The required data can be downloaded with the provided shell script.


Assumptions
-----------

 - act_dr6_cmbonly python module
 - ACT DR6 CMB-only data



Setup Parameters
----------------

None


Input values
----------------

.. list-table::
   :header-rows: 1

   * - Section
     - Name
     - Type
     - Default
     - Description

   * - cmb_cl
     - tt
     - real 1d
     - 
     - Lensed CMB temperature power spectrum in ell(ell+1)/2pi units
   * - 
     - te
     - real 1d
     - 
     - Lensed CMB temperature-E-mode polarization cross power spectrum in ell(ell+1)/2pi units
   * - 
     - ee
     - real 1d
     - 
     - Lensed CMB E-mode polaration power spectrum in ell(ell+1)/2pi units
   * - act_params
     - A_act
     - real
     - 1.0
     - Overall ACT calibration parameter used to model residual systematics.
   * - 
     - P_act
     - real
     - 1.0
     - Overall ACT polarisation efficiency parameter used to model residual systematics.


Output values
----------------


.. list-table:: Output values
   :header-rows: 1

   * - Section
     - Name
     - Type
     - Description

   * - likelihoods
     - act_dr6_lite_like
     - real
     - ACT DR6 primary CMB-only likelihood for given selection