# Halo-independence with quantified maximum entropy at DAMA/LIBRA

## Abstract

Using the DAMA/LIBRA anomaly as an example, we formalise the notion of halo-independence in the context of Bayesian statistics and quantified maximum entropy. We consider an infinite set of possible profiles, weighted by an entropic prior and constrained by a likelihood describing noisy measurements of modulated moments by DAMA/LIBRA. Assuming an isotropic dark matter (DM) profile in the galactic rest frame, we find the most plausible DM profiles and predictions for unmodulated signal rates at DAMA/LIBRA. The entropic prior contains an a priori unknown regularisation factor, β, that describes the strength of our conviction that the profile is approximately Maxwellian. By varying β, we smoothly interpolate between a halo-independent and a halo-dependent analysis, thus exploring the impact of prior information about the DM profile.

- Authors:

- ARC Centre of Excellence for Particle Physics at the Tera-scale, Monash University, Melbourne, Victoria 3800 (Australia)

- Publication Date:

- OSTI Identifier:
- 22667666

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 10; Other Information: Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; ENTROPY; FORECASTING; NONLUMINOUS MATTER; QUANTUM MECHANICS; STATISTICS

### Citation Formats

```
Fowlie, Andrew, E-mail: andrew.j.fowlie@googlemail.com.
```*Halo-independence with quantified maximum entropy at DAMA/LIBRA*. United States: N. p., 2017.
Web. doi:10.1088/1475-7516/2017/10/002.

```
Fowlie, Andrew, E-mail: andrew.j.fowlie@googlemail.com.
```*Halo-independence with quantified maximum entropy at DAMA/LIBRA*. United States. doi:10.1088/1475-7516/2017/10/002.

```
Fowlie, Andrew, E-mail: andrew.j.fowlie@googlemail.com. Sun .
"Halo-independence with quantified maximum entropy at DAMA/LIBRA". United States.
doi:10.1088/1475-7516/2017/10/002.
```

```
@article{osti_22667666,
```

title = {Halo-independence with quantified maximum entropy at DAMA/LIBRA},

author = {Fowlie, Andrew, E-mail: andrew.j.fowlie@googlemail.com},

abstractNote = {Using the DAMA/LIBRA anomaly as an example, we formalise the notion of halo-independence in the context of Bayesian statistics and quantified maximum entropy. We consider an infinite set of possible profiles, weighted by an entropic prior and constrained by a likelihood describing noisy measurements of modulated moments by DAMA/LIBRA. Assuming an isotropic dark matter (DM) profile in the galactic rest frame, we find the most plausible DM profiles and predictions for unmodulated signal rates at DAMA/LIBRA. The entropic prior contains an a priori unknown regularisation factor, β, that describes the strength of our conviction that the profile is approximately Maxwellian. By varying β, we smoothly interpolate between a halo-independent and a halo-dependent analysis, thus exploring the impact of prior information about the DM profile.},

doi = {10.1088/1475-7516/2017/10/002},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 10,

volume = 2017,

place = {United States},

year = {Sun Oct 01 00:00:00 EDT 2017},

month = {Sun Oct 01 00:00:00 EDT 2017}

}