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Recent results from Lattice QCD
Recent Lattice QCD results are reviewed with an emphasis on spectroscopic
results concerning the charm quark. It is demonstrated that, with accurate
computations from lattice QCD in recent years that can be compared with the
existing or upcoming experiments, stringent test of the Standard Model can be
performed which will greatly sharpen our knowledge on the strong interaction.Comment: 12 pages, 5 figures. Plenary talk presented at The XXXIII
international symposium on Physics in Collision (PIC2013), Institute of High
Energy Physics, Beijing, P. R. China, 03 - 07 September 201
On the K-theoretic classification of topological phases of matter
We present a rigorous and fully consistent -theoretic framework for
studying gapped topological phases of free fermions such as topological
insulators. It utilises and profits from powerful techniques in operator
-theory. From the point of view of symmetries, especially those of time
reversal, charge conjugation, and magnetic translations, operator -theory is
more general and natural than the commutative topological theory. Our approach
is model-independent, and only the symmetry data of the dynamics, which may
include information about disorder, is required. This data is completely
encoded in a suitable -superalgebra. From a representation-theoretic point
of view, symmetry-compatible gapped phases are classified by the
super-representation group of this symmetry algebra. Contrary to existing
literature, we do not use -theory to classify phases in an absolute sense,
but only relative to some arbitrary reference. -theory groups are better
thought of as groups of obstructions between homotopy classes of gapped phases.
Besides rectifying various inconsistencies in the existing literature on
-theory classification schemes, our treatment has conceptual simplicity in
its treatment of all symmetries equally. The Periodic Table of Kitaev is
exhibited as a special case within our framework, and we prove that the
phenomena of periodicity and dimension shifts are robust against disorder and
magnetic fields.Comment: 41 pages, revised version with a new abstract, introductory sections
and critique of the literatur
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