Parabolic Presentations of the Yangian

We introduce some new presentations for the Yangian associated to the Lie algebra These presentations are parametrized by tuples of positive integers summing to n. At one extreme, for the tuple (n), the presentation is the usual RTT presentation of Y_n. At the other extreme, for the tuple (1ⁿ), the presentation is closely related to Drinfelds presentation. In general, the presentations are useful for understanding the structure of the standard parabolic subalgebras of Y_n.Research partially supported by the NSF (grant no. DMS-0139019).Acknowledgement The second author would like to thank Arun Ram for stimulating conversations.