MATHEMATICAL METHODS IN THE APPLIED SCIENCES Math. Meth. Appl. Sci. 2002; 25:927–944 (DOI: 10.1002/mma.321) MOS subject classication: 35 Q 60; 45 A 05; 78 A 45 Electromagnetic scattering by a perfectly conducting obstacle in a homogeneous chiral environment: solvability and low-frequency theory C. Athanasiadis 1 , G. Costakis 2;† and I. G. Stratis 1;∗;‡ 1 Department of Mathematics; University of Athens; Panepistimiopolis; GR 157 84 Athens; Greece. 2 Department of Mathematics; University of Maryland; College Park; MD 20742; U.S.A. Communicated by G. F. Roach SUMMARY The scattering of plane time-harmonic electromagnetic waves propagating in a homogeneous isotropic chiral environment by a bounded perfectly conducting obstacle is studied. The unique solvability of the arising exterior boundary value problem is established by a boundary integral method. Integral representations of the total exterior eld, as well as of the left and right electric far-eld patterns are derived. A low-frequency theory for the approximation of the solution to the above problem, and the derivation of the far-eld patterns is also presented. Copyright ? 2002 John Wiley & Sons, Ltd. KEY WORDS: chiral media; boundary integral equation; integral representations; low-frequency; far-eld pattern 1. INTRODUCTION The absence of bilateral symmetry in the natural world was rst recognized historically through an appreciation of the mirror-image complementarity of enantiomeric molecules and the predominance of only one of the two optical isomers among the organic natural prod- ucts. Initially, the appreciation of handed complementation in enantiomers was conned to their gross morphological shape in the 1850s, and was extended to their detailed stereo- chemistry only a quarter of a century later. The prevelance of only one of the two pos- sible mirror-image enantiomers among natural organic products led Pasteur to postulate, and search for, the symmetric forces of nature. The notion of chirality has played a sine qua non role to the study of optical activity related to the above ideas. In recent years, ∗ Correspondence to: I. G. Stratis; Department of Mathematics; University of Athens; Panepistimiopolis; GR 157 84 Athens; Greece † E-mail: geokos@math.umd.edu ‡ E-mail: istratis@math.uoa.gr Contract=grant sponsor: Research Committee of the University of Athens; contract=grant no: 70=4=3408(CA), 70=4=5463(IGS) Copyright ? 2002 John Wiley & Sons, Ltd.