Merge pull request #134 from joezuntz/cmbshift

Add CMB shift parameter calculation to camb
joezuntz · Jul 12, 2024 · 1adfc6a · 1adfc6a
2 parents da7dcd7 + 9a6b59b
commit 1adfc6a
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 0 deletions.
diff --git a/boltzmann/camb/camb_interface.py b/boltzmann/camb/camb_interface.py
@@ -20,6 +20,7 @@
 
 DEFAULT_A_S = 2.1e-9
 
+C_KMS = 299792.458
 
 # See this table for description:
 #https://camb.readthedocs.io/en/latest/transfer_variables.html#transfer-variables
@@ -430,6 +431,9 @@ def save_derived_parameters(r, block):
     for k, v in derived.items():
         block[names.distances, k] = v
     block[names.distances, 'rs_zdrag'] = block[names.distances, 'rdrag']
+    zstar = derived['zstar']
+    shift = r.angular_diameter_distance(zstar) * (1 + zstar) * (p.omegam * p.H0**2)**0.5 / C_KMS
+    block[names.distances, "cmbshift"] = shift
 
     p.omegal = 1 - p.omegam - p.omk
     p.ommh2 = p.omegam * p.h**2

diff --git a/boltzmann/camb/module.yaml b/boltzmann/camb/module.yaml
@@ -513,6 +513,9 @@ outputs:
         thetarseq:
             meaning: Angle 100 r_s(eq)/DA(zstar)
             type: real
+        cmbshift:
+            meaning: CMB shift parameter equation 69 of Komatsu et al 2009
+            type: real
     growth_parameters:
         z:
             meaning: Redshift samples of other values in this section, (all if mode=power