Joint Institute for Computational Fundamental Science (JIC-FuS) is a collaborative effort eight institutions.
We had con-ducted nuclear calculations using quantum chromodynamics, simulations of neutron starmergers, and research on the gener-ation of density fluctuations in dark matter, under MEXT SPIRE
Field 5 “The origin of matter and the universe” imple-mented in fiscal 2015. JICFuS had gained somenoteworthy research results, winning the ACM Gordon Bell Prize.MEXT as “Priority Issue on Post-Kcomputer” (Elucidation of the Fundamental Laws and Evolution of the Universe) starts from fiscal 2016,・・

we aim to create further research results. JICFuS dedicated to enhancement of the computational science
research and development through (1) strong, fine-grained sup-port of fundamental computationalscientists, (2) provision of a venue for cooperation between fundamental computational sci-entists and・

computer scientists, and (3) creation of new fields of research.

The science of the Joint Institute for Computational Fundamental Science

Elucidation of the Fundamental Laws
and Evolution of the Universe

Quest for the Ultimate Laws and theBirth of the Universe

Exploring the Origin and Evolution ofMatterLarge-Scale Simulations andAstronomical Big Data

The ultimate purpose of computational science in thefields of particle physics, nuclear physics, and astrophysics
is to elucidate the history of the creation of matter, in amanner that bridges the three fields. Our aim is to conduct
precise lar ge-scale calculations using a supercomputer inorder to investigate phenomena on scales ranging from thatof elementary particles to the universe itself. We will com bine the results obtained with those of large-scale experi ments and observational data, in an ef fort to elucidate thehistory of the creation of matter.
To realize these aims, MEXT as “Priority Issue on Post-Kcomputer” (Elucidation of the Fundamental Laws andEvolution of the Universe), which will begin operation in
fiscal about 2020, will develop simulation code to verify
the Standard Model of particle physics, and investigate
superstring theory , particle interactions, the structure ofheavy nuclei, and stellar explosions, and so unlock themysteries of the evolution of the universe.

We plan to perform large-scale simulations of lattice qu an tum chromodynamics (QCD) in order to calculate the physi cal quantities needed to interpret the experimental results
obtained at la rge particle accelerators such as SuperKEKB
and J-PARC.

The purpose of this project is to explore the unsolved
issues in microscopic physics by larger-scale numericalcomputation. Specifically, the issues are to accurately deter mine the baryon-baryon interactions, nuclear structure andmany-body reactions between nuclei, and the equation ofstate for high-density nuclear matter.

In the next ten years, a variety of la rge observational
programs will be conducted. We will push the frontierof big data cosmology that combines observational data
and large-scale simulations to elucidate the evolution ofthe universe and the formation of galaxies.

Primary accomplishment

Primary accomplishment

Primary accomplishment

In the cooling process immediately following the birth of our hot

This is a simulation of the internal state of a massive and rapidly

Using the K computer, we computed the gravitational evolution

universe, there may have been a dramatic phase transition similarrotating neutron star formed by the merger of a neutron-starof approximately 550 billion dark-matter particles to reproduce

to the transformation of water into ice. Now, we have used large-binary. The figure one the left plots the density, while the figure on

the present dark-matter distribution of our universe confinedscale simulations involving lattice QCD—a model closely related

the right shows surfaces of constant magnetic-field strength. We

within a box of side length 5.4 billion light years (backgroundto the actual world in which we live—to shed light onto thissee that the shape of the star is distorted due to centrifugal forces;

image). The inset at the lower right shows the most massive

possibility. This figure plots the results of simulations conducted at

we also see that ultra-strong magnetic fields are produced in thedark-matter halo formed in this simulation, which is the size ofa temperature of 20 billion Kelvin, with the masses of the u andinterior, inducing a state of turbulent flow. This turbulent flow gives

a galaxy cluster. We see that many such halos are formed, andd quarks on the horizontal axis and topological fluctuations of therise to viscosity, which results in angular-momentum transport thatit is predicted that galaxies are formed at their centers andgluon field shown on the vertical axis. There is no question that

determines the star’ s ultimate fate.

black holes exist in the centers of the galaxies.

these simulations reveal new features that were previously unknown,
and we are working to push the techniques even further.

Depiction of a quark field in vacuum asobtained from a QCD simulation(©Guido Cossu)