Implementation of varying fundamental constants alpha and m_e

* devel:
  updated doxygen doc for the release of 3.1 (#66)
  defined Omega0_nfsm (non-free-streaming matter) used by HyRec; updated version number to 3.1.0 (#65)
  Fixing some small memory issues (uninitialized variables) for the varying fundamental constants. (#64)
  59 update hyrec bis (#61)
  Fixed a few more char sizes, as well as uninitialized variable errors.
  fixes issue #54
  Implementation of varying fundamental constants in CLASS (agrees with 1705.03925) (#56)
  Changed reference branch from master to devel (#58)

.github/workflows/test_on_pull_request.yml

@@ -14,7 +14,7 @@ jobs:
     - name: Checkout reference 🛎
       uses: actions/checkout@v2
       with:
-        ref: master
+        ref: devel
         path: ref_class
     - name: Create or update virtual Python environment
       run: |

explanatory.ini

@@ -265,6 +265,17 @@ reio_inter_xe = -2, -2, -1,  -1, 0.9, 0.5, 0.1,  0
 compute_damping_scale =
 
 
+# 10) State whether you want to include a variation of fudamental constants. Can be set to 'none' or to 'instantaneous'. Smoother evolutions could be included by modifying the function "background_varconst_of_z" in source/background.c.
+varying_fundamental_constants = none
+
+# 10.a) If 'varying_fundamental_constants' is set to 'instantaneous', select the redshift of the transition 'varying_transition_redshift' (default: 50). At lower redshift, the value will be the currently observed value, while at higher redshift you can specify how large the value should be by giving the ratio of the value at high redshift with respect to the currently observed one. Provide the relative value of the fine structure constant 'varying_alpha' (default: 1), and the relative value of the effective electron mass 'varying_me' (default: 1). The treatment corresponds to that of 1705.03925.
+varying_transition_redshift =
+varying_alpha = 1.
+varying_me = 1.
+
+# 10.b) If 'varying_fundamental_constants' is not set to 'none' and 'YHe' is set to 'BBN', specify by how much the 'YHe' prediction from 'BBN' should be affected by the different value of the fine structure constant. The default value is motivated by 2001.01787. (default: 1)
+bbn_alpha_sensitivity = 1.
+
 
 # -------------------------
 # ----> Species parameters:

external/HyRec2020/R_inf.dat

@@ -1,100 +1,100 @@
-  1.7280364e-270
-  6.6039762e-258
-  6.7635594e-246
-  1.9708577e-234
-  1.7300431e-223
-  4.8313008e-213
-  4.5215162e-203
-  1.4903791e-193
-  1.8142665e-184
-  8.5341394e-176
-  1.6197268e-167
-  1.2925969e-159
-  4.5115458e-152
-  7.1507716e-145
-  5.3349221e-138
-  1.9387643e-131
-  3.5460250e-125
-  3.3676825e-119
-  1.7109205e-113
-  4.7839499e-108
-  7.5646529e-103
-   6.9420654e-98
-   3.7898850e-93
-   1.2602397e-88
-   2.6106959e-84
-   3.4425222e-80
-   2.9493845e-76
-   1.6742940e-72
-   6.4165620e-69
-   1.6900470e-65
-   3.1118869e-62
-   4.0714008e-59
-   3.8441840e-56
-   2.6585412e-53
-   1.3658643e-50
-   5.2840064e-48
-   1.5592320e-45
-   3.5530007e-43
-   6.3258596e-41
-   8.8992663e-39
-   9.9988163e-37
-   9.0644363e-35
-   6.6952578e-33
-   4.0669811e-31
-   2.0498201e-29
-   8.6453638e-28
-   3.0760453e-26
-   9.3047039e-25
-   2.4105662e-23
-   5.3864587e-22
-   1.0451486e-20
-   1.7722856e-19
-   2.6426216e-18
-   3.4851890e-17
-   4.0882520e-16
-   4.2883440e-15
-   4.0429523e-14
-   3.4425611e-13
-   2.6598731e-12
-   1.8731305e-11
-   1.2073920e-10
-   7.1526105e-10
-   3.9093178e-09
-   1.9786383e-08
-   9.3067478e-08
-   4.0819149e-07
-   1.6748158e-06
-   6.4483254e-06
-   2.3365930e-05
-   7.9909245e-05
-   0.00025861567
-   0.00079408899
-    0.0023190028
-    0.0064559897
-     0.017171875
-     0.043730414
-      0.10683990
-      0.25089798
-      0.56736529
-       1.2375935
-       2.6082657
-       5.3193132
-       10.512952
-       20.163234
-       37.577705
-       68.135235
-       120.33502
-       207.23852
-       348.38577
-       572.25626
-       919.32050
-       1445.6878
-       2227.3000
-       3364.5516
-       4987.1358
-       7258.8380
-       10381.923
-       14600.711
-       20203.910
-       27525.291
+  1.7280364e-270
+  6.6039762e-258
+  6.7635594e-246
+  1.9708577e-234
+  1.7300431e-223
+  4.8313008e-213
+  4.5215162e-203
+  1.4903791e-193
+  1.8142665e-184
+  8.5341394e-176
+  1.6197268e-167
+  1.2925969e-159
+  4.5115458e-152
+  7.1507716e-145
+  5.3349221e-138
+  1.9387643e-131
+  3.5460250e-125
+  3.3676825e-119
+  1.7109205e-113
+  4.7839499e-108
+  7.5646529e-103
+   6.9420654e-98
+   3.7898850e-93
+   1.2602397e-88
+   2.6106959e-84
+   3.4425222e-80
+   2.9493845e-76
+   1.6742940e-72
+   6.4165620e-69
+   1.6900470e-65
+   3.1118869e-62
+   4.0714008e-59
+   3.8441840e-56
+   2.6585412e-53
+   1.3658643e-50
+   5.2840064e-48
+   1.5592320e-45
+   3.5530007e-43
+   6.3258596e-41
+   8.8992663e-39
+   9.9988163e-37
+   9.0644363e-35
+   6.6952578e-33
+   4.0669811e-31
+   2.0498201e-29
+   8.6453638e-28
+   3.0760453e-26
+   9.3047039e-25
+   2.4105662e-23
+   5.3864587e-22
+   1.0451486e-20
+   1.7722856e-19
+   2.6426216e-18
+   3.4851890e-17
+   4.0882520e-16
+   4.2883440e-15
+   4.0429523e-14
+   3.4425611e-13
+   2.6598731e-12
+   1.8731305e-11
+   1.2073920e-10
+   7.1526105e-10
+   3.9093178e-09
+   1.9786383e-08
+   9.3067478e-08
+   4.0819149e-07
+   1.6748158e-06
+   6.4483254e-06
+   2.3365930e-05
+   7.9909245e-05
+   0.00025861567
+   0.00079408899
+    0.0023190028
+    0.0064559897
+     0.017171875
+     0.043730414
+      0.10683990
+      0.25089798
+      0.56736529
+       1.2375935
+       2.6082657
+       5.3193132
+       10.512952
+       20.163234
+       37.577705
+       68.135235
+       120.33502
+       207.23852
+       348.38577
+       572.25626
+       919.32050
+       1445.6878
+       2227.3000
+       3364.5516
+       4987.1358
+       7258.8380
+       10381.923
+       14600.711
+       20203.910
+       27525.291