STATUS: Draft


Solving Polynomial Equations (15)


Aim: Explore the quartic equation and bBiTriQuad numbers


Ref: The BiTri array can be found on OEIS (A104978), seen in diagonals

Ref: Interesting related reference: John Zhau, Fat and Thin Emergent Geometries of Hermitial One-Matrix Models (math physics)

Observe: a solution to a general cubic equation

$$C(m_2, m_3) \equiv(-1)^{m_3 + 1} \frac{(2 m_{2} + 3 m_{3})!}{(1 + m_{2} + 2 m_{3})!m_2!m_3!} \frac{c_0^{1 + m_{2} + 2 m_{3}} c_2^{m_2} c_3^{m_3} }{c_1^{2 m_{2} + 3 m_{3} + 1}}$$

Create needed unknown types

Let $P1$, $P2$, $P3$ be from notebook 6.

Observe: $P2$ was presented in Notebook 6 as a general quartic equation. Subsitutions were made, replacing $c_0$ with $t$ and $x$ with $P1$

Observe: A solution for $x$ was found, $P3$.

Observe: The general form of each term in thesolution:

$$\frac{c_0^{m_0} c_2^{m_2} c_3^{m_3} c_4^{m_4}}{c_1^{m_1}} $$

Observe: Based on the data in the solution, 2 conditions for relationships between the $m_i$ terms can be seen:

Observe: the Degree of each term in the quartic satisfies: $m_0 + m_2 + m_3 + m_4 - m_1 = 0$

Observe: the Index Degree of each term in the quartic solution satisfied: $ m_1 + 2m_2 + 3m_3 + 4m_4 = -1$

Observe: It is possible to use these equations to create the following equivalencies:

$$m_0 = 1 + m_2 + 2m_3 + 3m_4 $$$$ m_1 = 1 + 2m_2 + 3m_3 + 4m_4 $$

Observe: these identities appear to be an extension of cubic case.

Observe: the General term is given by:

$$ F(m_2, m_3, m_4) = (-1)^{m_3 + 1} \frac{(2m_2 + 3m_3 + 4m_4)! }{(1 + m_2 + 2m_3 + 3m_4)!m_2!m_3!m_4!} \frac{c_0^{ 1 + m_2 + 2m_3 + 3m_4 } c_2^{m_2} c_3^{m_3} c_4^{m_4}}{c_1^{1 + 2m_2 + 3m_3 + 4m_4}} $$

Observe: This can be written equivalently in terms of $m, n, p$ to simplify subscripts in the variables.

$$ F(m, n, p) = (-1)^{n + 1} \frac{(2m + 3n + 4p)! }{(1 + m + 2n + 3p)!m!n!p!} \frac{c_0^{ 1 + m + 2n + 3p } c_2^{m} c_3^{n} c_4^{p}}{c_1^{1 + 2m + 3n + 4p}} $$

Let $F1$ be an implementation of $F$

Let $P6$ be an $8 \times 8 \times 1$ array of values evaluated with $F1$

Let $P8$ be an $8 \times 8 \times 1$ array of values evaluated with $F1$ returning coefficients only and ignoring signs

Observe: these coefficients can be regarded as BiTriQuad and are also sub multinomial

Observe: It is a natural conjecture, based on the assumption that if $m$ and $n$ relate to the number of ways of subdividing triangles and quadrilaterals, $p$ could relate to the number of ways of subdividing petagons. These numbers numbers may provide insight into the number of ways of subdividing polygons into triangles, quadrilaterals and pentagrams.

Observe: If this function is evaluated at $(m, n, 0)$ the BiTri (Catalan and Fuss numbers) will be recovered. This suggests a relatinoship between polynomials of increasing degrees.


Aim: Explore the BiTriQuad numbers in a similiar fashion to exploring the BiTri numbers

Method: Explore different combinations of inputs such as $m, m + 1, n, n + 1, p, p + 1$ and keeping one variables as this is a 3D array of numbers.


Observe: In the case of $(m, n, 1)$, the result given by $P8$, the first column of values is the OEIS entry A236194

Observe: In the case of $(m, n, 1)$, the result given by $P8$, the first row of values is the OEIS entry A002694

Todo: Check other patterns against OEIS

Conjecture: The BiTriQuad Numbers, which is the coeffiencts of F(m, n, p) counts the number of a diagonal subidivisons of a $(2 + m + 2n + 3p)$ sided polygon into $m$ triangles, $n$ quadrialterals and $p$ pentagons. In particular, this shows that $F(m, n, p)$ must a an integer

Observe: To "count" sides, start with 2, and then add one for every triangle that is being created. Quadrilaterals will add 2 new vertices/ edges Petagrams will add 3 vertices/edges. This is conjecture is true, this number will always be an integer.

Todo: Go through combinations in a similar way to the cubic case, and look at recursive relations.