A. Abdulle and S. Lemaire, An optimization-based method for sign-changing PDEs

A. Bonnet-ben-dhia, C. Carvalho, and P. Ciarlet-jr, Mesh requirements for the finite element approximation of problems with sign-changing coefficients, 2016.
URL : https://hal.archives-ouvertes.fr/hal-01335153

A. Bonnet-ben-dhia, L. Chesnel, and P. Ciarlet-jr, -coercivity for scalar interface problems between dielectrics and metamaterials, M2AN), pp.1363-1387, 2012.
DOI : 10.1051/m2an/2012006
URL : https://hal.archives-ouvertes.fr/hal-00717640

S. C. Brenner, Functions, SIAM Journal on Numerical Analysis, vol.41, issue.1, pp.306-324, 2003.
DOI : 10.1137/S0036142902401311
URL : https://hal.archives-ouvertes.fr/hal-01093487

L. Chesnel and P. Ciarlet-jr, T-coercivity and continuous Galerkin methods: application to transmission problems with sign changing coefficients, Numerische Mathematik, vol.54, issue.190, pp.1-29, 2013.
DOI : 10.1007/s00211-012-0510-8
URL : https://hal.archives-ouvertes.fr/hal-00688862

P. G. Ciarlet, The finite element method for elliptic problems, Classics in Applied Mathematics. Society for Industrial and Applied Mathematics (SIAM), vol.40, 2002.

M. D. Gunzburger, M. Heinkenschloss, and H. K. Lee, Solution of elliptic partial differential equations by an optimization-based domain decomposition method, Applied Mathematics and Computation, vol.113, issue.2-3, pp.111-139, 2000.
DOI : 10.1016/S0096-3003(99)00076-4

M. D. Gunzburger, J. S. Peterson, and H. K. Lee, An optimization based domain decomposition method for partial differential equations, Computers & Mathematics with Applications, vol.37, issue.10, pp.77-93, 1999.
DOI : 10.1016/S0898-1221(99)00127-3

H. Nguyen, Negative index materials and their applications: Recent mathematics progress, Chinese Annals of Mathematics
DOI : 10.1007/s11401-017-1086-5
URL : http://infoscience.epfl.ch/record/214971

H. Nguyen, Asymptotic behavior of solutions to the Helmholtz equations with sign-changing coefficients. Transactions of the, pp.6581-6595, 2015.

H. Nguyen, Limiting absorption principle and well-posedness for the Helmholtz equation with sign changing coefficients, Journal de Math??matiques Pures et Appliqu??es, vol.106, issue.2, pp.342-374, 2016.
DOI : 10.1016/j.matpur.2016.02.013

S. Nicaise and J. Venel, A posteriori error estimates for a finite element approximation of transmission problems with sign changing coefficients, Journal of Computational and Applied Mathematics, vol.235, issue.14, pp.4272-4282, 2011.
DOI : 10.1016/j.cam.2011.03.028
URL : https://hal.archives-ouvertes.fr/hal-00517989