Arroja, Frederico 艾若哲


Distinguished Junior Fellow

Home Institution



Ph.D. in Cosmology, Institute of Cosmology and Gravitation (ICG), University of Portsmouth, UK


R814, Astro-Math Building




- Istituto Nazionale di Fisica Nucleare (INFN) postdoctoral fellowship for foreign researchers (2012-2014)

- LFI core team member of the Planck collaboration (since June 2013)

- Japan Society for the Promotion of Science postdoctoral fellowship for foreign researchers (2008-2010)

- Science and Technology Foundation, Portugal PhD studentship (2004-2008)

- Faculty of Sciences of the University of Lisbon, BES prize for graduation with the best classification (2004)

- University of Lisbon, best classification of the Department of Physics (2002 and 2003)

- Foundation of Faculty of Sciences of the University of Lisbon, best first year classification of the Department of Physics (2001)


Current Research Interests

Cosmology: Models of the very early Universe like inflation and bouncing models. Computation of the non-Gaussianities using QFT in curved spacetime. Second order gravitational waves. Quantum gravity, e.g. Horava-Lifshitz gravity. Dark energy models. Constraining models with observational data and interpretation of constraints.

Models with extra-dimensions: Brane-World/String theory inspired models and observational predictions. Brane-Inflation. Low-energy effective theories.

Mathematical physics: Cosmological perturbation theory and dynamical systems techniques. QFT in curved spacetime.


Selected Publications

- M. Shiraishi, D. F. Mota, A. Ricciardone and F. Arroja, “CMB statistical anisotropy from noncommutative gravitational waves,” JCAP 1407 (2014) 047 [arXiv:1401.7936 [astro-ph.CO]].

- F. Arroja, N. Bartolo, E. Dimastrogiovanni and M. Fasiello, “On the Trispectrum of Galileon Inflation,” JCAP 1311 (2013) 005 [arXiv:1307.5371 [astro-ph.CO]].

- F. Arroja and M. Sasaki, “Strong scale dependent bispectrum in the Starobinsky model of inflation,” JCAP 1208 (2012) 012 [arXiv:1204.6489 [astro-ph.CO]].

- F. Arroja, A. E. Romano and M. Sasaki, “Large and strong scale dependent bispectrum in single field inflation from a sharp feature in the mass,” Phys. Rev. D84, 123503 (2011) [arXiv:1106.5384 [astro-ph.CO]].

- F. Arroja and T. Tanaka, “A note on the role of the boundary terms for the non-Gaussianity in general k-inflation,” JCAP 1105 (2011) 005 [arXiv:1103.1102 [astroph.CO]].

- F. Arroja and M. Sasaki, “A note on the equivalence of a barotropic perfect fluid with a K-essence scalar field,” Phys. Rev. D81 (2010) 107301 [arXiv:1002.1376 [astro-ph.CO]].

- K. Koyama and F. Arroja, “Pathological behaviour of the scalar graviton in Horava-Lifshitz gravity,” JHEP 1003 (2010) 061 [arXiv:0910.1998 [hep-th]].

- F. Arroja, H. Assadullahi, K. Koyama and D.Wands, “Cosmological matching conditions for gravitational waves at second order,” Phys. Rev. D80 (2009) 123526 [arXiv:0907.3618 [astro-ph.CO]].


I completed my PhD in the ICG in 2008. Then I had two-year postdoctoral positions in the Yukawa Institute for Theoretical Physics, Kyoto, in the Institute for the Early Universe, Seoul and finally, before joining LeCosPA, I had a two-year postdoctoral position at the INFN section of Padova. I am Portuguese and I was born on the 5th of September of 1982. In my free time I like to play football, hiking, riding my bicycle and travel. I enjoy the experience of living in different countries, meet new cultures and try their local food specialities.