70,765 research outputs found
Operator symbols and operator indices
We suggest a certain variant of symbolic calculus for special classes of linear bounded operators acting in Banach spaces. According to the calculus we formulate an index theorem and give applications to elliptic pseudo-differential operators on smooth manifolds with non-smooth boundarie
A-D-E Quivers and Baryonic Operators
We study baryonic operators of the gauge theory on multiple D3-branes at the
tip of the conifold orbifolded by a discrete subgroup Gamma of SU(2). The
string theory analysis predicts that the number and the order of the fixed
points of Gamma acting on S^2 are directly reflected in the spectrum of
baryonic operators on the corresponding quiver gauge theory constructed from
two Dynkin diagrams of the corresponding type. We confirm the prediction by
developing techniques to enumerate baryonic operators of the quiver gauge
theory which includes the gauge groups with different ranks. We also find that
the Seiberg dualities act on the baryonic operators in a non-Abelian fashion.Comment: 46 pages, 17 figures; v2: minor corrections, note added in section 1,
references adde
Hormander class of pseudo-differential operators on compact Lie groups and global hypoellipticity
In this paper we give several global characterisations of the Hormander class
of pseudo-differential operators on compact Lie groups. The result is applied
to give criteria for the ellipticity and the global hypoellipticity of
pseudo-differential operators in terms of their matrix-valued full symbols.
Several examples of the first and second order globally hypoelliptic
differential operators are given. Where the global hypoelliptiticy fails, one
can construct explicit examples based on the analysis of the global symbols.Comment: 20 page
From Principal Series to Finite-Dimensional Solutions of the Yang-Baxter Equation
We start from known solutions of the Yang-Baxter equation with a spectral
parameter defined on the tensor product of two infinite-dimensional principal
series representations of the group or Faddeev's
modular double. Then we describe its restriction to an irreducible
finite-dimensional representation in one or both spaces. In this way we obtain
very simple explicit formulas embracing rational and trigonometric
finite-dimensional solutions of the Yang-Baxter equation. Finally, we construct
these finite-dimensional solutions by means of the fusion procedure and find a
nice agreement between two approaches
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