Is there an on-line table of genus of algebraic functions?

In summary, the conversation is about finding an online table of genus for algebraic functions defined implicitly. The person is writing code and wants to check it against a standard source. They mention two examples of functions and their respective genus. They are not sure if their calculations are correct and suggest having an online table. However, the suggested source is not relevant as it deals with finite fields, while the functions being discussed involve polynomials in the field of complex numbers and convergent fractional power series.
  • #1
aheight
321
109
Hi,

Given the algebraic function ##w(z)## defined implicitly as ##f(z,w)=a_0(z)+a_1(z)w+a_2(z)w^2+\cdots+a_n(z)w^n=0##,
is there any on-line table of genus for them? Haven't been able to find anything. I am writing some code and would like to check it against a standard source. For example,
##f(z,w)=(z^4)+(2 z^2+z^4)w+(1+z^2+z^3)w^2+(z)w^3+(1/4-z/2)w^4+(-(1/2))w^5## has genus of 1 according to my calculations. And ##f(z,w)=(2+3 z-z^2)+(z^3+9 z^4)w+(-z-7 z^4)w^2+(-3 z)w^3+(2+4 z-4 z^3)w^4+(-8+z^2-7 z^3+3 z^4)w^5## has genus of 12. Not sure my calculations are correct. I am using the formula:

## g=1/2 \sum_{p} (r-1) -n+1##

Might be useful to have an on-line table I think. What do you guys think?

Thanks,
 
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  • #3

Related to Is there an on-line table of genus of algebraic functions?

1. What is a genus of an algebraic function?

The genus of an algebraic function is a measure of the complexity of the function, specifically the number of "holes" or handles on its graph. It is a topological invariant and is typically denoted by the letter g.

2. Why would someone need an online table of genus of algebraic functions?

An online table of genus of algebraic functions can be useful for researchers and mathematicians who are studying the properties and relationships between different functions. It can also be a helpful resource for students learning about algebraic functions and their characteristics.

3. Where can I find an on-line table of genus of algebraic functions?

There are several websites and online databases that have tables of genus of algebraic functions. Some examples include Wolfram MathWorld, The On-Line Encyclopedia of Integer Sequences, and The Electronic Journal of Combinatorics.

4. How is the genus of an algebraic function calculated?

The genus of an algebraic function can be calculated using the Riemann-Hurwitz formula, which takes into account the degrees and branch points of the function. It can also be determined by studying the function's graph and identifying the number of handles or holes.

5. Are there any other measures of complexity for algebraic functions?

Yes, there are other measures of complexity for algebraic functions, such as the degree of the function, the number of critical points, and the number of singularities. However, the genus is a particularly useful measure for understanding the topological properties of these functions.

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