Universality of representing power-sum sequences as supersymmetric Newton sums

Determine whether every sequence of power-sum variables p = (p1, p2, p3, …) can be represented in the form p_n = ∑_{i=1}^N (a_i^n − (−b_i)^n) for all n ≥ 1, for some integer N (possibly infinite) and complex sequences a = (a_1, …, a_N) and b = (b_1, …, b_N). Equivalently, ascertain whether any choice of power-sum data admits a realization as the supersymmetric Newton sums p(a/−b).

Background

The paper introduces the supersymmetric Newton sums parameterization p(a/−b), defined by p_n(a/−b) = ∑_{i=1}N (a_in − (−b_i)n), and uses it systematically to relate KP tau functions and correlators to BKP tau functions and correlators.

The author explicitly notes a conjectural universality: that any sequence of power-sum variables p might be realized as p(a/−b) for some N and coordinate sets a and b. Establishing this would justify the generality of the chosen parameterization and underpin the broad applicability of the bilinear KP–BKP relations developed in the paper.

References

One can easily conjecture that for any set $p=(p_1,p_2,\dots)$ there exits such a number $N$ (perhaps, infinite) and two sets $a=(a_1,\dots,a_N) $ and $b=(b_1,\dots,b_N)$ that (\ref{p=p(x,y)}) is true.

Bilinear Expansions of KP Multipair Correlators in BKP Correlators  (2401.06032 - Orlov, 2024) in Remark following equation (p=p(x,y)) in Subsection 'Few words about the problem', Section 1 (Introduction)