A truncated determinant algorithm is used to study the physical effects of the quark eigenmodes associated with eigenvalues below 400 MeV. This initial study focuses on coarse lattices (with O(a) improved gauge action), light internal quark masses and large physical volumes. Four bellwether full QCD processes are discussed: topological charge distributions, the eta prime propagator, string brea...

The study of Skyrmions predicts that there is an icosahedrally symmetric charge seventeen SU(2) Yang-Mills instanton in which the topological charge density, for fixed Euclidean time, is localized on the edges of the truncated icosahedron of the buckyball. In this paper the existence of such an instanton is proved by explicit construction of the associated ADHM data. A topological charge densit...

We study by numerical methods a particular kind of SU(N) Yang-Mills solutions of the Euclidean equations of motion which appear on the torus when twisted boundary conditions are imposed. These are instanton-like configurations with the peculiarity of having fractional topological charge. We focus on those solutions with minimal non-trivial action S = 8π/N and extract their properties in a few d...

We study the information metric on instanton moduli spaces in two-dimensional nonlinear σ models. In the CP 1 model, the information metric on the moduli space of one instanton with the topological charge Q = k (k ≥ 1) is a three-dimensional hyperbolic metric, which corresponds to Euclidean anti–de Sitter space-time metric in three dimensions, and the overall scale factor of the information met...

The short-range structure of the 2+1 flavour QCD vacuum is studied through visualisations of the topological charge density. Of particular interest is a new Gaussian weighted smearing algorithm which is applied to the rough topological charge density to disclose underlying long range structure. The results provide support for the view of the QCD vacuum as a sandwich of sign-alternating sheets o...

We demonstrate and discuss the connection between S-duality and string-theoretic picture-changing gauge transformation in the “infinite momentum frame”. The picturechanging transformation at zero momentum leads to the presence of the topological 5-form charge in the type IIB superalgebra (dimensionally reduced SUSY algebra of M-theory) which is attributed to the M5-brane. The topological charge...

A combinatorial formula to generate U (N) character expansions is presented. It is shown that the resulting character expansion formulas greatly simplify a number of problems where integrals over the group manifolds need to be calculated. Several examples are given, including direct and very quick calculations of the Itzykson-Zuber integral and the finite volume effective partition function of ...

The minimal sub-Planckian axion inflation model accounts for a large scalar-totensor ratio via a spiralling trajectory in the field space of a complex field Φ. Here we consider how the predictions of the model are modified by Planck scale-suppressed corrections. In the absence of Planck corrections the model is equivalent to a φ4/3 chaotic inflation model. Planck corrections become important wh...

We study the topological feature in the QCD vacuum based on the hypothesis of abelian dominance. The topological charge QSU(2) can be explicitly represented in terms of the monopole current in the abelian dominated system. To appreciate its justification, we directly measure the corresponding topological charge QMono, which is reconstructed only from the monopole current and the abelian compone...

We analyze the properties of a class of improved lattice topological charge density operators, constructed by a smearing-like procedure. By optimizing the choice of the parameters introduced in their definition, we find operators having (i) a better statistical behavior as estimators of the topological charge density on the lattice, i.e. less noisy; (ii) a multiplicative renormalization much cl...