Homeomorphism classes of compact 3-manifolds

In summary, the homeomorphism classes of compact 3-manifolds obtained from D^3 by identifying finitely many pairs of disjoint disks in the boundary can vary depending on the way the identification is done. However, the classes are independent of the way the resulting manifold is embedded in R³. Additionally, if the identification is orientation reversing, a solid Klein bottle can be obtained.
  • #1
pp31
10
0
Determine the homeomorphism classes of compact 3-manifolds obtained from D^3 by identifying finitely many pairs of disjoint disks in the boundary?


I just started reading some low dimensional topology on my own and I came across this question. I have realized that based on how the identification is done gives us various manifolds for instance if two disks are identified with identity map would give handlebody with unknotted handle. However I am having trouble determining the homeomorphism classes.

Any help would be appreciated.
Thanks
 
Physics news on Phys.org
  • #2
Maybe I'm missing something but if you identify one pair of disk, you get a solid torus. If you identify 2 pairs, you get a solid torus with two holes, etc.

the homeormorphism class is independant of the way you embed the resulting manifold in R³ (i.e. with knotted or unknotted handles). (Any two knots, no matter how knotted\twisted they are, are homeomorphic to each other. (They are not however, isotopic to each other.))
 
  • #3
quasar987 said:
Maybe I'm missing something but if you identify one pair of disk, you get a solid torus. If you identify 2 pairs, you get a solid torus with two holes, etc.

the homeormorphism class is independant of the way you embed the resulting manifold in R³ (i.e. with knotted or unknotted handles). (Any two knots, no matter how knotted\twisted they are, are homeomorphic to each other. (They are not however, isotopic to each other.))

I think if the identification is orientation preserving you are right. But if the identification is orientation reversing you do not get a multihandled solid torus.

If you glue the polar ice caps by a reflection around a great circle through the poles I think you get a solid Klein bottle.
 

Related to Homeomorphism classes of compact 3-manifolds

1. What is a homeomorphism class of a compact 3-manifold?

A homeomorphism class of a compact 3-manifold refers to the set of all topologically equivalent 3-dimensional spaces, where a homeomorphism is a continuous and invertible mapping between two spaces. In other words, all spaces in the same homeomorphism class can be continuously deformed into one another without tearing or gluing.

2. How do you determine the homeomorphism class of a compact 3-manifold?

The homeomorphism class of a compact 3-manifold can be determined by examining its topological properties, such as its fundamental group, orientability, and boundary structure. These properties can be used to distinguish between different homeomorphism classes.

3. Can two different compact 3-manifolds be in the same homeomorphism class?

No, two different compact 3-manifolds cannot be in the same homeomorphism class. This is because a homeomorphism is a one-to-one mapping, meaning that there can only be one topologically equivalent space for each homeomorphism class.

4. What are some examples of compact 3-manifolds and their homeomorphism classes?

Some examples of compact 3-manifolds and their homeomorphism classes include the 3-sphere, which is in the homeomorphism class of itself, and the 3-torus, which is in the same homeomorphism class as the Cartesian product of three circles. Other examples include the real projective 3-space, the complex projective plane, and the Klein bottle.

5. What is the significance of studying homeomorphism classes of compact 3-manifolds?

Studying homeomorphism classes of compact 3-manifolds is important in understanding the structure and properties of 3-dimensional spaces. It also has applications in fields such as topology, geometry, and physics. Additionally, it helps to classify and categorize different types of 3-manifolds, allowing for a deeper understanding of their topological and geometric properties.

Similar threads

  • Topology and Analysis
Replies
2
Views
2K
Replies
17
Views
2K
  • Differential Geometry
Replies
7
Views
5K
  • Differential Geometry
Replies
8
Views
2K
Replies
4
Views
2K
  • Differential Geometry
Replies
4
Views
3K
  • Topology and Analysis
2
Replies
38
Views
4K
  • Advanced Physics Homework Help
Replies
14
Views
1K
  • Differential Geometry
Replies
14
Views
3K
  • Differential Geometry
Replies
4
Views
3K
Back
Top