Ring of symmetric functions: Difference between revisions

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# The set of monomial symmetric functions parametrized by partitions form a basis of &Lambda;<sub>''R''</sub> as graded ''R''-[[module (mathematics)|module]], those parametrized by partitions of ''d'' being homogeneous of degree ''d''; the same is true for the set of Schur functions (also parametrized by partitions).
# &Lambda;<sub>''R''</sub> is [[isomorphic]] as a graded ''R''-algebra to a polynomial ring ''R''[''Y''<sub>1</sub>,''Y''<sub>2</sub>,…] in infinitely many variables, where ''Y''<sub>''i''</sub> is given degree&nbsp;''i'' for all ''i''&nbsp;&gt;&nbsp;0, one isomorphism being the one that sends ''Y''<sub>''i''</sub> to ''e''<sub>''i''</sub>&nbsp;&isin;&nbsp;&Lambda;<sub>''R''</sub> for every&nbsp;''i''.
# There is an [[Involution (mathematics)|involutaryinvolutory]] [[automorphism]] &omega; of &Lambda;<sub>''R''</sub> that interchanges the elementary symmetric functions ''e''<sub>''i''</sub> and the complete homogeneous symmetric function ''h''<sub>''i''</sub> for all ''i''. It also sends each power sum symmetric function ''p''<sub>''i''</sub> to (−1)<sup>''i''−1</sup>&nbsp;''p''<sub>''i''</sub>, and it permutes the Schur functions among each other, interchanging ''s''<sub>&lambda;</sub> and ''s''<sub>&lambda;<sup>t</sup></sub> where &lambda;<sup>t</sup> is the transpose partition of &lambda;.
 
Property 2 is the essence of the [[fundamental theorem of symmetric polynomials]]. It immediately implies some other properties: