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Two trace formulas for the spectra of arbitrary Hermitian matrices arederived by transforming the given Hermitian matrix $H$ to a unitary analogue.  In the first type the unitary matrix is $e^{i(\lambda\II - H)}$ where$\lambda$ is the spectral parameter. The new feature is that the spectralparameter appears in the final form as an argument of Eulerian polynomials --thus connecting the periodic orbits to combinatorial objects in a novel way. Toobtain the second type, one expresses the input in terms of a unitaryscattering matrix in a larger Hilbert space.  One of the surprising features here is that the locations and radii of thespectral discs of Gershgorin's theorem appear naturally as the pole parametersof the scattering matrix.  Both formulas are discussed and possible applications are outlined.

Trace formulas for general Hermitian matrices: Unitary scattering approach and periodic orbits on an associated graph