# On what scale should inflationary observables be constrained?

## Abstract

We examine the choice of scale at which constraints on inflationary observables are presented. We describe an implementation of the hierarchy of inflationary consistency equations which ensures that they remain enforced on different scales, and then seek to optimize the scale for presentation of constraints on marginalized inflationary parameters from WMAP3 data. For models with spectral index running, we find a strong variation of the constraints through the range of observational scales available, and optimize by finding the scale which decorrelates constraints on the spectral index n{sub S} and the running. This scale is k=0.017 Mpc{sup -1}, and gives a reduction by a factor of more than four in the allowed parameter area in the n{sub S}-r plane (r being the tensor-to-scalar ratio) relative to k=0.002 Mpc{sup -1}. These optimized constraints are similar to those obtained in the no-running case. We also extend the analysis to a larger compilation of data, finding essentially the same conclusions.

- Authors:

- Astronomy Centre, University of Sussex, Brighton BN1 9QH (United Kingdom)
- (South Africa)

- Publication Date:

- OSTI Identifier:
- 21020362

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.75.083520; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMOLOGY; INDEXES; INFLATIONARY UNIVERSE; SCALARS; TENSORS; VARIATIONS

### Citation Formats

```
Cortes, Marina, Cosmology and Gravity Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town, Liddle, Andrew R., and Mukherjee, Pia.
```*On what scale should inflationary observables be constrained?*. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVD.75.083520.

```
Cortes, Marina, Cosmology and Gravity Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town, Liddle, Andrew R., & Mukherjee, Pia.
```*On what scale should inflationary observables be constrained?*. United States. doi:10.1103/PHYSREVD.75.083520.

```
Cortes, Marina, Cosmology and Gravity Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town, Liddle, Andrew R., and Mukherjee, Pia. Sun .
"On what scale should inflationary observables be constrained?". United States.
doi:10.1103/PHYSREVD.75.083520.
```

```
@article{osti_21020362,
```

title = {On what scale should inflationary observables be constrained?},

author = {Cortes, Marina and Cosmology and Gravity Group, Department of Mathematics and Applied Mathematics, University of Cape Town, Cape Town and Liddle, Andrew R. and Mukherjee, Pia},

abstractNote = {We examine the choice of scale at which constraints on inflationary observables are presented. We describe an implementation of the hierarchy of inflationary consistency equations which ensures that they remain enforced on different scales, and then seek to optimize the scale for presentation of constraints on marginalized inflationary parameters from WMAP3 data. For models with spectral index running, we find a strong variation of the constraints through the range of observational scales available, and optimize by finding the scale which decorrelates constraints on the spectral index n{sub S} and the running. This scale is k=0.017 Mpc{sup -1}, and gives a reduction by a factor of more than four in the allowed parameter area in the n{sub S}-r plane (r being the tensor-to-scalar ratio) relative to k=0.002 Mpc{sup -1}. These optimized constraints are similar to those obtained in the no-running case. We also extend the analysis to a larger compilation of data, finding essentially the same conclusions.},

doi = {10.1103/PHYSREVD.75.083520},

journal = {Physical Review. D, Particles Fields},

number = 8,

volume = 75,

place = {United States},

year = {Sun Apr 15 00:00:00 EDT 2007},

month = {Sun Apr 15 00:00:00 EDT 2007}

}