An Etymological Dictionary of Astronomy and Astrophysics
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The → covariance of a → time series overt time.

→ auto-; → covariance.

The autocovariance function (ACF) is defined as the sequence of covariances of a stationary process.
A mathematical function that expresses the autocovariance of a series in terms of the interval of separation.

→ autocovariance; → function.

The → electric charge carried by an object is independent of the → velocity of the object with respect to the → observer. In other words, the charge is the same in any → frame of reference.

→ charge; → invariance.

In statistics, a measure of linear dependence. For two random variables X and Y with expectations m_x and m_y, the covariance is E{(X - m_x)(Y - m_y)}.

From co-, → com-, + → variance.

From ham-, → com-, + vartâyi, → variance.

Same as → Galilean relativity.

→ Galilean; → invariance.

The invariance of any field theory under gauge transformation.

→ gauge; → invariance.

Any property of a physical law or quantity that is unchanged after the application of certain classes of transformations.

Invariance; noun of → invariant.

→ Einstein equivalence principle.

→ local; → Lorentz; → invariance.

→ Einstein equivalence principle.

→ local; → position; → invariance.

Of a physical law, invariance with respect to a → Lorentz transformation.

→ Lorentz; → invariance.

In special relativity, the principle that the laws of physics take the same mathematical form in all inertial frames of reference.

→ principle; → covariance.

A measure of the scatter of the values of a random variable (X) about its mean (μ). Var(X) = E(X -μ)². The positive square root of the variance is called the → standard deviation.

M.E., from O.Fr. variance, from L. variantia, from variare "to change," → vary.

Vartâyi quality noun from vartâ agent noun from vartidan, → vary.