The B36/S125 "2x2" Life-Like Cellular Automaton

The B36/S125 (or "2x2") cellular automaton is one that takes place on a 2D square lattice much like Conway's Game of Life. Although it exhibits high-level behaviour that is similar to Life, such as chaotic but eventually stable evolution and the existence of a natural diagonal glider, the individual objects that the rule contains generally look very different from their Life counterparts. In this article, a history of notable discoveries in the 2x2 rule is provided, and the fundamental patterns of the automaton are described. Some theoretical results are derived along the way, including a proof that the speed limits for diagonal and orthogonal spaceships in this rule are c/3 and c/2, respectively. A Margolus block cellular automaton that 2x2 emulates is investigated, and in particular a family of oscillators made up entirely of 2 x 2 blocks are analyzed and used to show that there exist oscillators with period 2^m(2^k - 1) for any integers m,k \geq 1.Comment: 18 pages, 19 figure

Baryons 2002: Outlook

Summary and outlook presented at the 9th International Conference on the Structure of Baryons (BARYONS 2002), Jefferson Lab, March 3-8, 2002Comment: 10 pages, to be publ.in: Proceedings Int. Conf. BARYONS 2002, Jefferson Lab., March 200

Yukawa's Pion, Low-Energy QCD and Nuclear Chiral Dynamics

A survey is given of the evolution from Yukawa's early work, via the understanding of the pion as a Nambu-Goldstone boson of spontaneously broken chiral symmetry in QCD, to modern developments in the theory of the nucleus based on the chiral effective field theory representing QCD in its low-energy limit.Comment: 21 pages, 13 figures. Proc. Yukawa-Tomonaga Symposium, Kyoto, Dec.06; to be publ. in Progr. Theor. Phys. Suppl. (Kyoto

Dense Baryonic Matter and Strangeness in Neutron Stars

Recent developments of chiral effective field theory (ChEFT) applications to nuclear and neutron matter are summarized, with special emphasis on a (non-perturbative) extension using functional renormalisation group methods. Topics include: nuclear thermodynamics, extrapolations to dense baryonic matter and constraints from neutron star observables. Hyperon-nuclear interactions derived from SU(3) will be discussed with reference to the "hyperon puzzle" in neutron star matter.Comment: 17 pages, 7 figures; invited talk at the Int. Conf. on Quarks and Nuclear Physics (QNP 2018), Tsukuba, Japan; to appear in JPS Conf. Pro