The UPARCOS-UCM unit (Particle Physics and Cosmos Unit at UCM) was created on September 27, 2016, by the union of the five officially recognized research groups of Universidad Complutense de Madrid:

- GAE: High Energy Physics. PIs: F. Arqueros and M. López Moya.

- GFN: Nuclear Physics. PIs: J. M. Udías and L.M. Fraile.

- GUAIX: Extragalactic and Instrumental Astrophysics. PI: J. Gallego.

- SEEF: Stellar Systems, Spectroscopy and Photometry. PI: D. Montes.

- TEFM: Effective theories, Particle Physics and Cosmology. PIs: A. Dobado and A. Gómez Nicola.

Long before their organization turned into the UPARCOS unit, these groups had already collaborated in the framework of two Consolider-Ingenio large-scale national projects, CPAN and MultiDark, and the AstroMadrid R&D program of the Community of Madrid. Moreover, a strong collaboration has also been maintained in postgraduate training in Masters's and Doctorate programs. Throughout 2016, numerous meetings were held between these groups to explore ways of intensifying these collaborations that finally led to the creation of UPARCOS, approved on September 29, 2016, by the UCM Government Council.

The unit’s first goal was to strengthen the collaboration among the groups to identify potential synergies and foster scientific exchanges. To this end, several collaborative activities were programmed. From the organizational point of view, creating a Research Institute to structure the unit further was seen as advantageous.

As a result of two-year work, the Institute of Particle and Cosmos Physics (IPARCOS) was founded and approved by the Government Council of UCM on December 18, 2018.

One of the consequences of these initiatives was the attraction of talent so that from the initial size of 28 doctors in 2016, the unit has grown up to a current size more than 70 researcher staff members (as of March 2024) and 30 PhD students. Many new members are young researchers newly hired with competitive funding from excellence programs (RyC, CM Talent, Maria Zambrano contract, etc.).

Some pics from IPARCOS congresses in 2023 and 2022.