scholarly journals Toward a Combinatorial Proof of the Jacobian Conjecture!

10.37236/2023 ◽  
2011 ◽  
Vol 18 (2) ◽  
Author(s):  
Dan Singer

The Jacobian conjecture [Keller, Monatsh. Math. Phys., 1939] gives rise to a problem in combinatorial linear algebra: Is the vector space generated by rooted trees spanned by forest shuffle vectors? In order to make headway on this problem we must study the algebraic and combinatorial properties of rooted trees. We prove three theorems about the vector space generated by binary rooted trees: Shuffle vectors of fixed length forests are linearly independent, shuffle vectors of nondegenerate forests relative to a fixed tree are linearly independent, and shuffle vectors of sufficient length forests are linearly independent. These results are proved using the acyclic digraph method for establishing that a coefficient matrix has full rank [Singer, The Electronic Journal of Combinatorics, 2009]. We also provide an infinite class of counterexamples to demonstrate the need for sufficient length in the third theorem.

Author(s):  
D. J. A. Welsh

AbstractKruskal's theorem for obtaining a minimal (maximal) spanning tree of a graph is shown to be a special case of a more general theorem for matroid spaces in which each element of the matroid has an associated weight. Since any finite subset of a vector space can be regarded as a matroid space this theorem gives an easy method of selecting a linearly independent set of vectors of minimal (maximal) weight.


1974 ◽  
Vol 18 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Robert I. Soare

Terminology and notation may be found in Dekker [1] and [2]. Briefly, we fix a recursively enumerable (r.e.) field F with recursive structure, and let Ū be the vector space over F consisting of ultimately vanishing countable sequences of elements of F with the usual definitions of vector addition and multiplication by a scalar. A subspace V of Ū is called an α-space if V has a basis B which is contained in some r.e. linearly independent set S.


Author(s):  
Tapani Matala-aho

Given a sequence of linear forms in m ≥ 2 complex or p-adic numbers α1, …,αm ∈ Kv with appropriate growth conditions, Nesterenko proved a lower bound for the dimension d of the vector space Kα1 + ··· + Kαm over K, when K = Q and v is the infinite place. We shall generalize Nesterenko's dimension estimate over number fields K with appropriate places v, if the lower bound condition for |Rn| is replaced by the determinant condition. For the q-series approximations also a linear independence measure is given for the d linearly independent numbers. As an application we prove that the initial values F(t), F(qt), …, F(qm−1t) of the linear homogeneous q-functional equation where N = N(q, t), Pi = Pi(q, t) ∈ K[q, t] (i = 1, …, m), generate a vector space of dimension d ≥ 2 over K under some conditions for the coefficient polynomials, the solution F(t) and t, q ∈ K*.


10.37236/1890 ◽  
2005 ◽  
Vol 11 (2) ◽  
Author(s):  
Seunghyun Seo

In this paper, we give a simple combinatorial explanation of a formula of A. Postnikov relating bicolored rooted trees to bicolored binary trees. We also present generalized formulas for the number of labeled $k$-ary trees, rooted labeled trees, and labeled plane trees.


1984 ◽  
Vol 27 (4) ◽  
pp. 490-493 ◽  
Author(s):  
David Grow ◽  
William C. Whicher

AbstractThe analogue of Horn's theorem characterizing finite unions of linearly independent sets in a vector space is shown to fail in the group of integers.


1987 ◽  
Vol 41 (2) ◽  
pp. 227-234 ◽  
Author(s):  
H. Bruce Friedrich ◽  
Jung-Pin Yu

A factor analysis of a set of spectra of multicomponent mixtures yields n orthogonal spectra where n is the number of components in the mixtures. Combinations of these orthogonal spectra, done so as to eliminate the contributions to the spectra from one of the components, yield a set of n – 1 linearly independent abstract spectra. Repetition of this process is used to estimate the spectrum of each of the components without identifying the range of the n-dimensional vector space in which the solution must fall. Several techniques for estimating the appropriate combinations of orthogonal spectra are compared.


1959 ◽  
Vol 11 (3) ◽  
pp. 139-141 ◽  
Author(s):  
A. P. Robertson ◽  
J. D. Weston

The well-known “basis theorem” of elementary algebra states that in a finite-dimensional vector space, any two bases have the same number of elements; or, equivalently, that a vector space is n-dimensional if it has a basis consisting of n vectors (where the dimension of a vector space is defined to be the least upper bound of the numbers k for which there exist k linearty independent vectors, and a basis is defined to be a maximal set of linearly independent vectors). This theorem has an analogue in the theory of groups : if an Abelian group has a finite maximal set of independent non-cyclic elements, the number of elements in one such set being n, then no set of independent non-cyclic elements can have more than n members.


BIBECHANA ◽  
2013 ◽  
Vol 10 ◽  
pp. 115-117
Author(s):  
Nagendra Pd Sah

A vector space X with algebra of all linear maps ∑(X) from X into itself and the ideal of all finite dimensional linear maps with dual (Conjugate) transformation T* to T from X' to itself form a relation in terms of relatively regular and linearly independent which is sufficient for mentioned title. DOI: http://dx.doi.org/10.3126/bibechana.v10i0.9342   BIBECHANA 10 (2014) 115-117


10.37236/1546 ◽  
2000 ◽  
Vol 8 (1) ◽  
Author(s):  
Dan Singer

New combinatorial properties of Catalan trees are established and used to prove a number of algebraic results related to the Jacobian conjecture. Let $F=(x_1+H_1,x_2+H_2,\dots,x_n+H_n)$ be a system of $n$ polynomials in $C[x_1,x_2,\dots,x_n]$, the ring of polynomials in the variables $x_1,x_2, \dots, x_n$ over the field of complex numbers. Let $H=(H_1,H_2,\dots,H_n)$. Our principal algebraic result is that if the Jacobian of $F$ is equal to 1, the polynomials $H_i$ are each homogeneous of total degree 2, and $({{\partial H_i}\over {\partial x_j}})^3=0$, then $H\circ H\circ H=0$ and $F$ has an inverse of the form $G=(G_1,G_2,\dots,G_n)$, where each $G_i$ is a polynomial of total degree $\le6$. We prove this by showing that the sum of weights of Catalan trees over certain equivalence classes is equal to zero. We also show that if all of the polynomials $H_i$ are homogeneous of the same total degree $d\ge2$ and $({{\partial H_i}\over {\partial x_j}})^2=0$, then $H\circ H=0$ and the inverse of $F$ is $G=(x_1-H_1,\dots,x_n-H_n)$.


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