Let F∗ n be the set of Boolean functions depending on all n variables. We prove that for any f ∈ F∗ n, f |xi=0 or f |xi=1 depends on the remaining n − 1 variables, for some variable xi. This existent result suggests a possible way to deal with general Boolean functions via its subfunctions of some restrictions. As an application, we consider the degree lower bound of representing polynomials ov...

In this paper we introduce a family of polynomials indexed by pairs of partitions and show that if these polynomials are self-orthogonal then the centre of the Iwahori-Hecke algebra of the symmetric group is precisely the set of symmetric polynomials in the Murphy operators.

f(T1, . . . , Tn) = f(Tσ(1), . . . , Tσ(n)) for all σ ∈ Sn. Example 1. The sum T1 + · · ·+ Tn and product T1 · · ·Tn are symmetric, as are the power sums T r 1 + · · ·+ T r n for any r ≥ 1. As a measure of how symmetric a polynomial is, we introduce an action of Sn on F [T1, . . . , Tn]: (σf)(T1, . . . , Tn) = f(Tσ−1(1), . . . , Tσ−1(n)). We need σ−1 rather than σ on the right side so this is a...

Let n ≥ 2 and Tn be the space of n × n real skew-symmetric matrices. For each θ ∈ Tn the corresponding n-dimensional noncommutative torus Aθ is defined as the universal C-algebra generated by unitaries U1, · · · , Un satisfying the relation UkUj = e(θkj)UjUk, where e(t) = e. Noncommutative tori are one of the canonical examples in noncommutative differential geometry [12, 2]. One may also consi...

University of Sydney 3.

We introduce the maximumskew-symmetric ow problem which generalizes ow and matching problems. We develop a theory of skew-symmetric ows that is parallel to the classical ow theory. We use the newly developed theory to extend, in a natural way, the blocking ow method of Dinitz to the skew-symmetric ow case. In the special case of the skew-symmetric ow problem that corresponds to cardinality matc...

The study contributes to the cross-linguistic discussion on the prosodic correlates and categorial status of contrastive focus. It brings in data from Estonian, a flexible word order language where the prosodic expression of Information Structure has been very little studied. The study compares narrow contrastive focus with narrow and broad information focus in semi-spontaneous production data,...

Knop and Sahi simultaneously introduced a family of non-homogeneous, non-symmetric polynomials, Gα(x; q, t). The top homogeneous components of these polynomials are the non-symmetric Macdonald polynomials, Eα(x; q, t). An appropriate Hecke algebra symmetrization of Eα yields the Macdonald polynomials, Pλ(x; q, t). A search for explicit formulas for the polynomials Gα(x; q, t) led to the main re...