Does every topological manifold have a smooth structure? It is well known that not every topological 4-manifold admits a smooth structure. Is every manifold smooth? Every smooth manifold is a topological manifold, but not necessarily

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## Does every topological manifold have a smooth structure?

It is well known that not every topological 4-manifold admits a smooth structure.

## Is every manifold smooth?

Every smooth manifold is a topological manifold, but not necessarily vice versa. (The first nonsmooth topological manifold occurs in four dimensions.) Milnor (1956) showed that a seven-dimensional hypersphere can be made into a smooth manifold in 28 ways. Bredon, G. E. Topology & Geometry.

## Are manifolds topological spaces?

Topological manifolds are an important class of topological spaces, with applications throughout mathematics. All manifolds are topological manifolds by definition.

## What is a smooth structure on a manifold?

Definition. A smooth structure on a manifold is a collection of smoothly equivalent smooth atlases. Here, a smooth atlas for a topological manifold is an atlas for such that each transition function is a smooth map, and two smooth atlases for.

## What is not a manifold?

Non-manifold geometry is defined as any edge shared by more than two faces. This can occur when a face or edge is extruded but not moved, which results in two identical edges directly on top of one another.

## Is a cone a smooth manifold?

The single cone can be very easily be considered a smooth manifold.

## Is the real line a manifold?

The real line is trivially a topological manifold of dimension 1. Up to homeomorphism, it is one of only two different connected 1-manifolds without boundary, the other being the circle. It also has a standard differentiable structure on it, making it a differentiable manifold.

## Is a cone a topological manifold?

Cone is a topological manifold.

## What are the different types of nail abnormalities?

Nail Abnormalities 1 Healthy nails appear smooth and have consistent coloring. 2 Abnormalities of the fingernail. Some changes in your nails are due to medical conditions… 3 Beau’s lines. Depressions that run across your fingernail are called Beau’s lines. 4 Clubbing. Clubbing is when your nails thicken and curve around your…

## Is it normal to have vertical ridges on your nails?

As you age, you may develop vertical ridges, or your nails may be a bit more brittle. This is harmless. Spots due to injury should grow out with the nail.

## What makes your nails thicken and curve around your fingertips?

Clubbing is when your nails thicken and curve around your fingertips, a process that generally takes years. This can be the result of low oxygen in the blood and is associated with: cardiovascular diseases. inflammatory bowel disease. liver diseases. pulmonary diseases. AIDS.

## Can a medical condition change the appearance of your fingernails?

Certain medical conditions can also change the appearance of your fingernails. However, these changes can be difficult to interpret. Your fingernails’ appearance alone isn’t enough to diagnose a specific illness.