# What Are The Covariant Quantities

## What are the covariant quantities?

The covariant quantities are scalar fields, vector fields, tensor fields etc., defined on spacetime considered as a manifold. Main example of covariant equation is the Einstein field equations.

## What is covariant in science?

Covariance is defined as a measure of how much two variables change together. In the context of genetics, the variables are specific positions on the genome, for example, two base pairs or two genes.

## What is covariant and contravariant in physics?

In differential geometry, the components of a vector relative to a basis of the tangent bundle are covariant if they change with the same linear transformation as a change of basis. They are contravariant if they change by the inverse transformation.

## Is covariance mean?

For two jointly distributed real-valued random variables and with finite second moments, the covariance is defined as the expected value (or mean) of the product of their deviations from their individual expected values: where is the expected value of , also known as the mean of .

## What is covariance also called?

A covariance matrix is also known as the auto-covariance matrix, variance matrix, dispersion matrix, or variance-covariance matrix.

## What is the difference between covariant and invariant?

The word “covariant” is commonly used when talking about the “form” of physical equations. “Invariant” is more commonly used when talking about an actual quantity.

## What is the covariant law of physics?

A physical law expressed in a generally covariant fashion takes the same mathematical form in all coordinate systems, and is usually expressed in terms of tensor fields. The classical (non-quantum) theory of electrodynamics is one theory that has such a formulation.

## What is covariant tensor in physics?

A covariant tensor, denoted with a lowered index (e.g., ) is a tensor having specific transformation properties. In general, these transformation properties differ from those of a contravariant tensor.

## What is contravariant and covariant quantity?

Contravariant vectors describe those quantities where the distance units comes at the numerator (like velocity), whereas covariant are those where the distance unit is at the denominator (like temperature gradient). These are, of course, just fancy mathematical names.

## What is covariance with example?

Covariance is a statistical tool used to determine the relationship between the movements of two random variables. When two stocks tend to move together, they are seen as having a positive covariance; when they move inversely, the covariance is negative.

## Can covariance be 0?

Zero covariance – if the two random variables are independent, the covariance will be zero. However, a covariance of zero does not necessarily mean that the variables are independent. A nonlinear relationship can exist that still would result in a covariance value of zero.

## Is covariance greater than 1?

Unlike correlation, covariance values do not have a limit between -1 and 1.