antisymmetric

adjective

1. not comparable, of a binary relation R on a set S Having the property that, for any two distinct elements of S, at least one is not related to the other via R; equivalently, having the property that, for any x, y ∈ S, if both xRy and yRx then x=y. 1987, David C. Buchthal, Douglas E. Cameron, Modern Abstract Algebra, Prindle, Weber & Schmidt, page 479, The standard example for an antisymmetric relation is the relation less than or equal to on the real number system.
2. not comparable, of a matrix, of certain mathematical objects Whose transpose equals its negative (i.e., Mᵀ = −M); The eigenvalues of an antisymmetric matrix are all purely imaginary numbers, and occur as conjugate pairs, #43;iw and -iw. As a corollary it follows that an antisymmetric matrix of odd order necessarily has one eigenvalue equal to zero; antisymmetric matrices of odd order are singular.
3. not comparable, of a tensor, of certain mathematical objects That changes sign when any two indices are interchanged (e.g., Tᵢⱼₖ = -Tⱼᵢₖ); Notice that the tensors defined by: #92;textstyleT#95;S#92;equiv#92;frac#123;1#125;#123;2#125;(T#43;Tᵀ), #92;textstyleT#95;A#92;equiv#92;frac#123;1#125;#123;2#125;(T-Tᵀ), (3.47) are the symmetric and antisymmetric parts, respectively; they are known as the symmetric and antisymmetric parts of T.
4. not comparable, of a bilinear form, of certain mathematical objects For which B(w,v) = -B(v,w). Antisymmetric bilinear forms and wedge products are defined exactly as above, only now they are functions from #92;Rⁿ#92;times#92;Rⁿ to #92;R.[…] Exercise 21 Show that every antisymmetric bilinear form on #92;R³ is a wedge product of two covectors.

Similar: skew-symmetric