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Keywords:
indefinite numerical range; indefinite inner product space; plane algebraic curve
Summary:
The point equation of the associated curve of the indefinite numerical range is derived, following Fiedler's approach for definite inner product spaces. The classification of the associated curve is presented in the $3\times 3$ indefinite case, using Newton's classification of cubic curves. Illustrative examples of all the different possibilities are given. The results obtained extend to Krein spaces results of Kippenhahn on the classical numerical range.
References:
[1] Ball, W. W. R.: On Newton's classification of cubic curves. Proc. London Math. Soc. 22 (1890), 104-143 \JFM 23.0778.05.
[2] Bebiano, N., Lemos, R., Providência, J. da, Soares, G.: On generalized numerical ranges of operators on an indefinite inner product space. Linear and Multilinear Algebra 52 (2004), 203-233. DOI 10.1080/0308108031000134981 | MR 2074863
[3] Bebiano, N., Lemos, R., Providência, J. da, Soares, G.: On the geometry of numerical ranges in spaces with an indefinite inner product. Linear Algebra Appl. 399 (2005), 17-34. MR 2152407
[4] Brieskorn, E., Knörrer, H.: Plane Algebraic Curves. Birkhäuser Verlag, Basel (1986). MR 0886476
[5] Fiedler, M.: Geometry of the numerical range of matrices. Linear Algebra Appl. 37 (1981), 81-96. DOI 10.1016/0024-3795(81)90169-5 | MR 0636211 | Zbl 0452.15024
[6] Horn, R. A., Johnson, C. R.: Matrix Analysis. Cambridge University Press, New York (1985). MR 0832183 | Zbl 0576.15001
[7] Horn, R. A., Johnson, C. R.: Topics in Matrix Analysis. Cambridge University Press, New York (1991). MR 1091716 | Zbl 0729.15001
[8] Kippenhahn, R.: Über den Wertevorrat einer Matrix. Math. Nachr. 6 (1951), 193-228. DOI 10.1002/mana.19510060306 | MR 0059242 | Zbl 0044.16201
[9] Li, C.-K., Rodman, L.: Numerical range of matrix polynomials. SIAM J. Matrix Anal. Appl. 15 (1994), 1256-1265. DOI 10.1137/S0895479893249630 | MR 1293915 | Zbl 0814.15023
[10] Li, C.-K., Rodman, L.: Shapes and computer generation of numerical ranges of Krein space operators. Electr. J. Linear Algebra 3 (1998), 31-47. MR 1617817 | Zbl 0905.47027
[11] Li, C.-K., Tsing, N. K., Uhlig, F.: Numerical ranges of an operator in an indefinite inner product space. Electr. J. Linear Algebra 1 (1996), 1-17. MR 1401906
[12] Murnaghan, F. D.: On the field of values of a square matrix. Proc. Nat. Acad. Sci. USA 18 (1932), 246-248. DOI 10.1073/pnas.18.3.246 | Zbl 0004.05003
[13] Nakazato, H., Bebiano, N., Providência, J. da: The $J$-Numerical Range of a $J$-Hermitian Matrix and Related Inequalities. Linear Algebra Appl. 428 (2008), 2995-3014. MR 2416604
[14] Nakazato, H., Psarrakos, P.: On the shape of numerical range of matrix polynomials. Linear Algebra Appl. 338 (2001), 105-123. DOI 10.1016/S0024-3795(01)00374-3 | MR 1861116 | Zbl 0996.15018
[15] Psarrakos, P.: Numerical range of linear pencils. Linear Algebra Appl. 317 (2000), 127-141. DOI 10.1016/S0024-3795(00)00145-2 | MR 1782206 | Zbl 0966.15014
[16] Shapiro, H.: A conjecture of Kippenhahn about the characteristic polynomial of a pencil generated by two Hermitian matrices. II. Linear Algebra Appl. 45 (1982), 97-108. DOI 10.1016/0024-3795(82)90212-9 | MR 0660980 | Zbl 0495.15007
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