Covariant and Contravariant Tensors

In summary, covariant and contravariant tensors are two types of tensors that behave differently under a change of basis. Covariant tensors vary in scale when the basis changes, while contravariant tensors do not. This can be visualized by considering a change of coordinates in a curvilinear system, where the tangent and normal vectors form two distinct bases. In simpler terms, a change of coordinates in Cartesian tensors can be represented by multiplying the vector by an invertible square matrix on the left.
  • #1
putongren
121
0
Not sure where to post this thread.

That being said, can someone explain to me simply what covariant and contravariant tensors are and how covariant and contravariant transformation works? My understanding of it from googling these two mathematical concepts is that when you change the basis of these two tensors, the scale of the resultant varies differently between the two. Please use simple to understand examples.

Thank you.
 
Last edited:
Mathematics news on Phys.org
  • #3
putongren said:
That being said, can someone explain to me simply what covariant and contravariant tensors are and how covariant and contravariant transformation works?

We could begin with Cartesian tensors. In that context, do you understand how a change of coordinates applied to a column vector can be represented by multiplying the vector on the left by an invertible square matrix ?
 

1. What is the difference between covariant and contravariant tensors?

Covariant and contravariant tensors are two different types of tensors in mathematics and physics. The main difference between them is how they transform under a change of coordinates. Covariant tensors change their components in the same way as the coordinates, while contravariant tensors change their components in the opposite way to the coordinates. This means that the components of a covariant tensor will have the same transformation rules as the basis vectors, while the components of a contravariant tensor will have the same transformation rules as the basis covectors.

2. How are covariant and contravariant tensors related to each other?

Covariant and contravariant tensors are related through the metric tensor, which gives the inner product between vectors. The metric tensor can be used to raise or lower indices of a tensor, converting it from covariant to contravariant, or vice versa. This allows for the conversion between the two types of tensors and is crucial in many areas of physics and mathematics.

3. What is the significance of covariant and contravariant tensors in general relativity?

In general relativity, covariant and contravariant tensors play a crucial role in the formulation of the theory. The theory is based on the principle of covariance, which states that the laws of physics should be the same in all reference frames. This is achieved by using covariant and contravariant tensors to describe the geometry of spacetime, allowing for the formulation of the famous Einstein's field equations.

4. Can covariant and contravariant tensors be represented graphically?

Yes, covariant and contravariant tensors can be represented graphically using arrow diagrams. Covariant tensors are represented by arrows pointing downwards, while contravariant tensors are represented by arrows pointing upwards. The length of the arrow represents the magnitude of the tensor, and the direction represents the transformation properties of the components under a change of coordinates.

5. How are covariant and contravariant tensors used in practical applications?

Covariant and contravariant tensors are used in various practical applications, including in physics, engineering, and computer science. In physics, they are used to describe the properties of spacetime and the laws of motion, while in engineering, they are used to describe stress and strain in materials. In computer science, they are used in machine learning and image recognition algorithms. Overall, covariant and contravariant tensors are powerful mathematical tools that have a wide range of applications in various fields.

Similar threads

  • General Math
Replies
5
Views
1K
  • Advanced Physics Homework Help
Replies
5
Views
2K
Replies
24
Views
1K
  • Special and General Relativity
Replies
10
Views
2K
Replies
16
Views
3K
  • Other Physics Topics
Replies
8
Views
8K
  • Special and General Relativity
Replies
3
Views
859
  • Special and General Relativity
2
Replies
36
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
Replies
1
Views
1K
Back
Top