s Arnau's Homepage

Hi world, Arnau Rios speaking!

I am a theoretical physicist working at the University of Surrey. Surf the upper panel to find information about who I am and the research I carry on.
Students or post-docs interested in carrying out a research project on theoretical nuclear and astronuclear physics and looking for funding opportunities, please contact me.


Yuri Oganessian visits Surrey 14/03/2018

Surrey will host the visit of an illustrious scientist: Yuri Oganessian. He is directly or indirectly responsible for the discovery of several new elements - mostly those in the island of stability of superheavy elements with more than 100 protons. This has been recognised by the IUPAC, that named element 118 Oganesson, Og, in his honour. Professor Oganessian will deliver a talk at 4:30 pm in 01AC01. I am certainly attending - will you?

Matthew Barton becomes a doctor 07/02/2018

Matthew Barton has successfully held his PhD thesis viva today. His work on time-dependent Hartree-Fock techniques has been published in a paper here and a preprint here. His thesis dealt with a more complex beyond-mean-field theory, time-dependent density matrix, and was a feat in terms of both physics output and computational developments.

Congratulations Matthew!


Outreach on neutron star binaries 21/11/2017

On Tuesday November 21 from 6:30 pm, I will be participating in an outreach event on the Gravitational Wave discovery GW170817 as announced here. LIGO's latest gravitational wave detection has spawned an explosion of new science across the global astronomical community. I plan to focus on how this tells us about neutron stars and the creation of the elements. My colleague Rob Izzard from the astrophysics group will discuss how these events come into being in binary stellar systems.


Farewell to NewCompStar 08/11/2017

Today I bid farewell to the NewCompStar COST action. It has been a very interesting 4 years, with several meetings, conferences, workshops and summer schools. To me, the real value of this action has been the interdisciplinary components:meeting with colleagues of the astrohysics community to discuss and progress our understanding on neutron stars. The farewell coincides with the discovery of the binary GW170817 in gravitational waves and across the electromagnetic spectrum, which opens a new window into neutron stars... I have tried to summarise the progress on equation of state in the NewCompStar era in the review talk here in a nice meeting in Catania.


Crust-core transition and Gogny forces 12/06/2017

Neutron stars are like chocolat fondants: solid in the outside and liquid in the inside. The neutron liquid sea turns into a solid crystaline lattice of nuclei at the so-called crust-core transition point. The density at which this transition occurs is correlated to experimental properties of nuclei. In this paper with the nuclear physics group in Barcelona, we explore the range of crust-core transitions predicted by Gogny nuclear interactions and look an neutron-star properties as well (like the mass-radius relation in the picture on the left). More details here.


Nuclear spectral functions and chiral forces 10/02/2017

Spectral functions characterise the properties of nucleons in dense matter. They provide a unique insight into nuclear correlations and can be used to access both thermodynamical and structural properties. We have found a way to characterise spectral functions and provide a link to chiral nuclear hamiltonians by looking at the size and shape of the spectral function's standard deviations. All explained in more detail in here!


Outreach 03/08/2016


Here's the talk that I gave at the TEDx Event "Redifining the Ordinary" on 27 February 2016. I hope you enjoy it!




Di-neutrons? Yes, please 16/02/2016

Di-neutrons are loosely bound states of two neutrons. They do not exist in free-space, but they can appear in dense nuclear media. In a preprint in collaboration with Felipe Isaule (who visited Surrey for a month on Jan 2015) and Prof. Hugo Arellano, we report on the first microscopic results on the structure of di-neutrons in neutron matter.


Fission paper out 01/02/2016

My second paper on nuclear fission, with results from Phil Goddard's thesis and in collaboration with Paul Stevenson, has now been published here. Have a look to see what you can do with 3D TDHF and boosts!


Rosh Sellahewa becomes a doctor 12/11/2015

Roshan Sellahewa, (co-supervised with Jim Al-Khalili) has successfully held his thesis viva today. His work on neutron star physics and the Gogny interaction has been published here. And there are more papers to come, even though Rosh has moved on to pastures new. Congratulations Rosh!


Fission week! 28/10/2015

This website has been on a standstill during my paternity leave on the summer of 2015 - but I am back to work! I have decided to dub this week "Fission week": my first paper on fission has been accepted for publication in Phys. Rev. C, and the second one is out now as a preprint. All these results were cooked up by Phil Goddard, a former PhD student that now does more useful stuff!


Pairing gap and correlations 23/02/2015

The pairing gap in high-density neutron matter is sensite to short- and long-range correlations. Some new results on these effects are presented in a preprint, written with collaborators at Washington University in St. Louis.


Phil Goddard becomes a doctor 26/09/2014

Arnau's second PhD student, Phil Goddard, (co-supervised with Paul Stevenson) has successfully held his thesis viva today. Congratulations Phil!


Gogny forces and neutron stars 31/07/2014

The first paper from Rosh Sellahewa's PhD is now out. Check it out if you are interested on Gogny forces or neutron stars! It's here.


Propagating errors at finite T 15/07/2014

Arnau's first paper with Xavier Roca-Maza looks at error propagation in "hot" density functional theory. Have a look at it here.


Arianna Carbone becomes a doctor 11/04/2014

Arnau's first PhD student, Arianna Carbone, (co-supervised with Artur Polls) has successfully defended her thesis. Feel free to have a look at it here.


Creative Commons Paper 04/04/2014

Arnau first open access (CC licence) paper has been published today.


Post @ Surrey Physics Blog 03/01/2014

Arnau has written a post on the 10th-year anniversary of the Close Encounters of the PhD King. Check it out here.


High-momentum components in nuclear matter 02/01/2014

Arnau has submitted a paper on the density and isospin asymmetry dependence of short-range correlations. It has implications for electron scattering experiments. Check it here.


ECT* Workshop 22/08/2013

Arnau is organizing a workshop on "Advances in time-dependent methods for quantum many-body systems" at the ECT* in Trento this coming October. Registration is now open.


ISNET Workshop 21/08/2013

Thanks everyone for attending the workshop on "ISNET: Information and Statistics in Nuclear Experiment and Theory" at the University of Glasgow. Talks are available here.


IAS Workshop 13/08/2013

Thanks everyone for attending the workshop on "Neutron Stars" at the Institute of Advanced Studies. It was a terrific meeting! Talks and photos are available here.


Chiral three-nucleon forces 22/07/2013

Arianna Carbone's PhD thesis is going forward. Check this paper for our latest results involving three-body forces within the Green's functions approach.


Pygmy dipole resonance in Selenium 03/05/2013

Arnau's first paper with nuclear experimentalists!


Why is lead so kinky? 10/10/2012

If you ever wondered why lead is so kinky, have a look at this preprint!

Update: the paper is now published in Phys. Rev. Lett. and there is a talk available.


IoP One-Day Meeting 21/03/2013

Arnau is organizing a meeting on "Correlations in exotic nuclear systems" at the Cockroft Institute, Daresbury Laboratory. This will be a meeting point for experimentalists and theorists interested in the evolution of correlations with isospin asymmetry, including everything from shell changes to symmetry energy studies. Contact me if you are interested in participating!


IoP SOUTH CENTRAL BRANCH LECTURE 13/03/2013

Arnau gave an outreach IoP Lecture on neutron stars at the University of Surrey. Thanks to all of those who attended it!
Link to the talk: pdf

More news

30 July 2012: Arnau's first paper with the Catania group has been submitted!

9 July 2012: Check out Arnau's outreach talk on the Higg's boson

10 January 2012: Arnau's first EPL has been published

6 January 2012: Arnau's first Phys. Rev. Lett. has been published