I am an Assistant Professor at the Centre for Astrophysics and Cosmology at the University of Iceland. I recently moved from the Dark Cosmology Centre of the Niels Bohr Institute, University of Copenhagen, where I was a Marie Curie Fellow (2013-2016). Previously, I had a joint postdoctoral position at the Perimeter Institute for Theoretical Physics and the Department of Physics and Astronomy, University of Waterloo (2010-2013).

My research interests are related broadly to two topics, the intrinsic nature of dark matter, and its impact on the formation, evolution and properties of galaxies.

Curriculum Vitae (download PDF)





Research

From early 2014 to early 2016, I kept a blog related to my Marie Curie research project. You can find the blog in this address .

Going beyond the CDM model. The current paradigm of structure formation, the Cold Dark Matter (CDM) model, assumes that dark matter is collisionless and cold (with very low thermal motions). Observations of the abundance and properties of dwarf galaxies might be challenging these hypothesis. I have been interested in testing alternative models where dark matter is assumed to be warm (Warm Dark Matter, WDM) or self-colisional (Self-Interacting Dark Matter, SIDM). These extensions to the CDM model share its successes in reproducing the large-scale structure of the Universe, and have the potential of solving the small-scale problems.

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Projected dark matter density at z=0 for simulations of the local Universe in a WDM model (left) and of a Milky-Way-size dark matter halo in a SIDM model (right).

Associated articles:
ApJ, 2009, 700, 1779
MNRAS, 2012, 423, 3740
MNRAS, 2013, 430, 1722
MNRAS Letters, 2013, 431, L20
MNRAS, 2014, 444, 3684
PRD, 2014, 90, 043524


Dark matter annihilation. Although there is substantial evidence for the existence of dark matter from its gravitational effects in the visible ordinary matter, a definitive proof requires a non-gravitational signature. I have been interested in the prospect of such detection by looking for the byproducts of the hypothetical annihilation of dark matter.

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Full-sky maps of the gamma-ray radiation background expected from the annihilation of dark matter in extragalactic structures (left) and in the smooth galactic halo (right).

Associated news and articles:
MPA Research highlights October 2009
MNRAS, 2010, 405, 593
PRD, 2011, 83, 123513
MNRAS, 2013, 429, 1529


Recently, together with Niayesh Afshordi, I have developed a model to compute the Particle Phase Space Average Density (P2SAD) in galactic haloes, a novel measure of the clustering of dark matter introduced in Zavala & Afshordi 2013a. Our model for P2SAD, calibrated with state-of-the-art N-body simulations, can be used to estimate signals sensitive to the nanostructure of dark matter distributions (e.g. dark matter annihilation). A description of the model is given in Zavala & Afshordi 2013b, while an IDL code that computes P2SAD with our model is publicly available at this link.

In Zavala 2014, I proposed a novel idea to explain the cosmic high-energy neutrinos recently discovered by the IceCube collaboration based on dark matter annihilation. I show that this is viable possibility, wrongly disregarded in the past, and compute the corresponding predicted signal using P2SAD.