CW complex for infinite holed torus? (Surface of infinite genus)

In summary: Projective limits could also be a useful tool in visualizing the infinite case, but it may require some more advanced understanding of topology. Overall, the key is to remember that the CW complex for the infinite case will have infinitely many 2-cells, representing the infinite number of holes in the manifold. In summary, the CW complex for an infinite n-genus orientable manifold would have one 0-cell, 2n 1-cells, and infinitely many 2-cells, with the fundamental group being a free group with 2n generators. Visualizing it may be challenging, but looking at images of CW complexes for higher genus manifolds and using projective limits could be helpful.
  • #1
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I am just trying to figure out how to make a CW complex for this. For the n-genus orientable manifold (connect sum of n-tori) I feel like a lot of things make sense, fundamental group, CW complex, etc. But in the infinite case, things seem to fall apart. For example, I can not figure out how the fundamental group is a free group. I was hoping to figure this out by first looking at the CW complex of this surface, but I'm not sure I can picture it.


IN a finite case, I just have a single 0 cell (1 vertex), 2n 1-cells, and a single 2 cell. BUt does this hold at the infinite case? If not what's an alternate way to visualize it?
 
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  • #2
I would consider projective limits here, although I'm not sure this would help. To precisely determine where and why "things fall apart" would also be of great help.
 
  • #3


I'm not an expert in topology, but I'll try my best to help. From my understanding, the CW complex for an n-genus orientable manifold would have one 0-cell (representing the single connected component), 2n 1-cells (representing the n-tori), and an infinite number of 2-cells (representing the infinite number of holes in the manifold). Each 1-cell would attach to the 0-cell, and each 2-cell would attach to the boundary of the 1-cells.

As for the fundamental group being a free group, I believe this is because the 1-cells (representing the n-tori) are all disjoint from each other and can be freely deformed without changing the fundamental group. This means that the fundamental group is generated by the 1-cells, and since there are 2n 1-cells, the fundamental group is a free group with 2n generators.

I hope this helps a bit in understanding the CW complex for the infinite case. As for visualizing it, I think it might be helpful to look at some images or diagrams of CW complexes for orientable manifolds with higher genus, and then try to imagine extending that to the infinite case.
 

1. What is a CW complex for an infinite holed torus?

A CW complex for an infinite holed torus is a mathematical structure that represents the surface of an infinite genus torus, which is a surface with an infinite number of holes. It is constructed by attaching cells of different dimensions (0-cells, 1-cells, 2-cells, etc.) to a base space using specific attaching maps.

2. How is a CW complex for an infinite holed torus different from a finite holed torus?

A CW complex for an infinite holed torus is different from a finite holed torus in that it has an infinite number of holes, while a finite holed torus only has a finite number of holes. This means that the CW complex for an infinite holed torus is a more complex mathematical structure and requires a different construction process.

3. What are the applications of a CW complex for an infinite holed torus?

A CW complex for an infinite holed torus has applications in topology, geometry, and mathematical physics. It can be used to study the properties of surfaces with an infinite number of holes, which have many interesting and unique characteristics. It also has applications in the study of higher-dimensional spaces and their properties.

4. How is a CW complex for an infinite holed torus visualized?

A CW complex for an infinite holed torus can be visualized by drawing its 1-skeleton, which is the collection of all 0-cells and 1-cells that make up the surface. This gives a simplified representation of the surface and helps to understand its topological properties. However, it is important to note that the full CW complex cannot be visualized as it has an infinite number of cells.

5. What are some interesting properties of a CW complex for an infinite holed torus?

A CW complex for an infinite holed torus has many interesting properties, such as being non-orientable, having a non-trivial fundamental group, and being homeomorphic to a plane with an infinite number of holes. It also has an infinite number of 1-cells and 2-cells, which gives it a highly complex and intricate structure. Additionally, it has applications in knot theory, as it can be used to represent and study infinitely knotted surfaces.

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