On the continuity and differentiability of the (dual) core inverse in C*-algebras

[EN] The continuity of the core inverse and the dual core inverse is studied in the setting of -algebras. Later, this study is specialized to the case of bounded Hilbert space operators and to complex matrices. In addition, the differentiability of these generalized inverses is studied in the context of -algebras.The third author is supported by the Scientific Research Foundation for doctorate programme at Huaiyin Institute of Technology [grant number Z301B18534]. The third author is grateful to China Scholarship Council for helping him pursue his further study at Universitat Politècnica de València, SpainBenítez López, J.; Boasso, E.; Xu, S. (2020). On the continuity and differentiability of the (dual) core inverse in C*-algebras. Linear and Multilinear Algebra. 68(4):686-709. https://doi.org/10.1080/03081087.2018.1516187S686709684Baksalary, O. M., & Trenkler, G. (2010). Core inverse of matrices. Linear and Multilinear Algebra, 58(6), 681-697. doi:10.1080/03081080902778222Rakić, D. S., Dinčić, N. Č., & Djordjević, D. S. (2014). Group, Moore–Penrose, core and dual core inverse in rings with involution. Linear Algebra and its Applications, 463, 115-133. doi:10.1016/j.laa.2014.09.003Rakić, D. S., Dinčić, N. Č., & Djordjević, D. S. (2014). Core inverse and core partial order of Hilbert space operators. Applied Mathematics and Computation, 244, 283-302. doi:10.1016/j.amc.2014.06.112Xu, S., Chen, J., & Zhang, X. (2016). New characterizations for core inverses in rings with involution. Frontiers of Mathematics in China, 12(1), 231-246. doi:10.1007/s11464-016-0591-2Drazin, M. P. (2012). A class of outer generalized inverses. Linear Algebra and its Applications, 436(7), 1909-1923. doi:10.1016/j.laa.2011.09.004Boasso, E., & Kantún-Montiel, G. (2017). The (b, c)-Inverse in Rings and in the Banach Context. Mediterranean Journal of Mathematics, 14(3). doi:10.1007/s00009-017-0910-1Harte, R. (1992). On generalized inverses in C*-algebras. Studia Mathematica, 103(1), 71-77. doi:10.4064/sm-103-1-71-77Harte, R. (1993). Generalized inverses in C*-algebras II. Studia Mathematica, 106(2), 129-138. doi:10.4064/sm-106-2-129-138Penrose, R. (1955). A generalized inverse for matrices. Mathematical Proceedings of the Cambridge Philosophical Society, 51(3), 406-413. doi:10.1017/s0305004100030401Mbekhta, M. (1992). Conorme et Inverse Généralisé Dans Les C*-Algèbres. Canadian Mathematical Bulletin, 35(4), 515-522. doi:10.4153/cmb-1992-068-8Du, F., & Xue, Y. (2012). Perturbation analysis of A_{T,S}^(2) on Banach Spaces. The Electronic Journal of Linear Algebra, 23. doi:10.13001/1081-3810.1543Benítez, J., Cvetković-Ilić, D., & Liu, X. (2014). On the continuity of the group inverse in $C^*$-algebras. Banach Journal of Mathematical Analysis, 8(2), 204-213. doi:10.15352/bjma/1396640064Benítez, J., & Cvetković-Ilić, D. (2013). On the elements aa† and a†a in a ring. Applied Mathematics and Computation, 222, 478-489. doi:10.1016/j.amc.2013.07.015Koliha, J. J. (2001). Continuity and differentiability of the Moore-Penrose inverse in $C^*$-algebras. MATHEMATICA SCANDINAVICA, 88(1), 154. doi:10.7146/math.scand.a-14320Koliha, J. J., & Rakočević, V. (2004). On the Norm of Idempotents in $C^*$ -Algebras. Rocky Mountain Journal of Mathematics, 34(2). doi:10.1216/rmjm/1181069874Benítez, J., & Liu, X. (2012). On the continuity of the group inverse. Operators and Matrices, (4), 859-868. doi:10.7153/oam-06-55Douglas, R. G. (1966). On majorization, factorization, and range inclusion of operators on Hilbert space. Proceedings of the American Mathematical Society, 17(2), 413-413. doi:10.1090/s0002-9939-1966-0203464-1Boasso, E. (2009). Drazin spectra of Banach space operators and Banach algebra elements. Journal of Mathematical Analysis and Applications, 359(1), 48-55. doi:10.1016/j.jmaa.2009.05.036Rakić, D. S. (2017). A note on Rao and Mitra’s constrained inverse and Drazin’s (b,c) inverse. Linear Algebra and its Applications, 523, 102-108. doi:10.1016/j.laa.2017.02.025Stewart, G. W. (1969). On the Continuity of the Generalized Inverse. SIAM Journal on Applied Mathematics, 17(1), 33-45. doi:10.1137/011700

Generalized backscattering and the Lax-Phillips transform

Using the free-space translation representation (modified Radon transform) of Lax and Phillips in odd dimensions, it is shown that the generalized backscattering transform (so outgoing angle $\omega =S\theta$ in terms of the incoming angle with $S$ orthogonal and \Id-S invertible) may be further restricted to give an entire, globally Fredholm, operator on appropriate Sobolev spaces of potentials with compact support. As a corollary we show that the modified backscattering map is a local isomorphism near elements of a generic set of potentials.Comment: Minor changes, typos corrected, references adde

Generalized quantum potentials in scale relativity

We first recall that the system of fluid mechanics equations (Euler and continuity) that describes a fluid in irrotational motion subjected to a generalized quantum potential (in which the constant is no longer reduced to the standard quantum constant hbar) is equivalent to a generalized Schrodinger equation. Then we show that, even in the case of the presence of vorticity, it is also possible to obtain, for a large class of systems, a Schrodinger-like equation of the vectorial field type from the continuity and Euler equations including a quantum potential. The same kind of transformation also applies to a classical charged fluid subjected to an electromagnetic field and to an additional potential having the form of a quantum potential. Such a fluid can therefore be described by an equation of the Ginzburg-Landau type, and is expected to show some superconducting-like properties. Moreover, a Schrodinger form can be obtained for the fluctuating rotational motion of a solid. In this case the mass is replaced by the tensor of inertia, and a generalized form of the quantum potential is derived. We finally reconsider the case of a standard diffusion process, and we show that, after a change of variable, the diffusion equation can also be given the form of a continuity and Euler system including an additional potential energy. Since this potential is exactly the opposite of a quantum potential, the quantum behavior may be considered, in this context, as an anti-diffusion.Comment: 33 pages, submitted for publicatio