Initial power spectra¶
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class
isitgr.initialpower.
InitialPower
[source]¶ Abstract base class for initial power spectrum classes
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class
isitgr.initialpower.
InitialPowerLaw
(**kwargs)[source]¶ Bases:
isitgr.initialpower.InitialPower
Object to store parameters for the primordial power spectrum in the standard power law expansion.
Variables: - tensor_parameterization – (integer/string, one of: tensor_param_indeptilt, tensor_param_rpivot, tensor_param_AT)
- ns – (float64)
- nrun – (float64)
- nrunrun – (float64)
- nt – (float64)
- ntrun – (float64)
- r – (float64)
- pivot_scalar – (float64)
- pivot_tensor – (float64)
- As – (float64)
- At – (float64)
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has_tensors
()[source]¶ Do these settings have non-zero tensors?
Returns: True if non-zero tensor amplitude
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set_params
(As=2e-09, ns=0.96, nrun=0, nrunrun=0.0, r=0.0, nt=None, ntrun=0.0, pivot_scalar=0.05, pivot_tensor=0.05, parameterization='tensor_param_rpivot')[source]¶ Set parameters using standard power law parameterization. If nt=None, uses inflation consistency relation.
Parameters: - As – comoving curvature power at k=pivot_scalar (\(A_s\))
- ns – scalar spectral index \(n_s\)
- nrun – running of scalar spectral index \(d n_s/d \log k\)
- nrunrun – running of running of spectral index, \(d^2 n_s/d (\log k)^2\)
- r – tensor to scalar ratio at pivot
- nt – tensor spectral index \(n_t\). If None, set using inflation consistency
- ntrun – running of tensor spectral index
- pivot_scalar – pivot scale for scalar spectrum
- pivot_tensor – pivot scale for tensor spectrum
- parameterization – See CAMB notes. One of - tensor_param_indeptilt = 1 - tensor_param_rpivot = 2 - tensor_param_AT = 3
Returns: self
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class
isitgr.initialpower.
SplinedInitialPower
(**kwargs)[source]¶ Bases:
isitgr.initialpower.InitialPower
Object to store a generic primordial spectrum set from a set of sampled k_i, P(k_i) values
Variables: effective_ns_for_nonlinear – (float64) Effective n_s to use for approximate non-linear correction models -
set_scalar_log_regular
(kmin, kmax, PK)[source]¶ Set log-regular cublic spline interpolation for P(k)
Parameters: - kmin – minimum k value (not minimum log(k))
- kmax – maximum k value (inclusive)
- PK – array of scalar power spectrum values, with PK[0]=P(kmin) and PK[-1]=P(kmax)
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set_scalar_table
(k, PK)[source]¶ Set arrays of k and P(k) values for cublic spline interpolation. Note that using
set_scalar_log_regular()
may be better (faster, and easier to get fine enough spacing a low k)Parameters: - k – array of k values (Mpc^{-1})
- PK – array of scalar power spectrum values
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