%0 Journal Article %T On the R-matrix realization of Yangians and their representations %A D. Arnaudon %A A. Molev %A E. Ragoucy %J Mathematics %D 2005 %I arXiv %R 10.1007/s00023-006-0281-9 %X We study the Yangians Y(a) associated with the simple Lie algebras a of type B, C or D. The algebra Y(a) can be regarded as a quotient of the extended Yangian X(a) whose defining relations are written in an R-matrix form. In this paper we are concerned with the algebraic structure and representations of the algebra X(a). We prove an analog of the Poincare-Birkhoff-Witt theorem for X(a) and show that the Yangian Y(a) can be realized as a subalgebra of X(a). Furthermore, we give an independent proof of the classification theorem for the finite-dimensional irreducible representations of X(a) which implies the corresponding theorem of Drinfeld for the Yangians Y(a). We also give explicit constructions for all fundamental representation of the Yangians. %U http://arxiv.org/abs/math/0511481v1