A Greek lambda, denoting the distance between successive wave peaks.
Also known as: Lambda, Upside-down y
λ is wavelength in optics and acoustics, the decay constant in nuclear physics, and an eigenvalue in linear algebra. A reader who meets it deserves all three, not whichever a textbook happens to teach first.
Denotes wavelength: the distance over which a wave's shape repeats, measured between successive corresponding points.
Contexts: Mathematics, Laboratory
Denotes the decay constant in nuclear physics — the probability per unit time that a nucleus decays — which is a rate rather than a length and shares only the letter.
Contexts: Mathematics, Laboratory
Denotes an eigenvalue in linear algebra, a third unrelated use in the same body of scientific writing.
Contexts: Mathematics
The lower-case Greek letter lambda: a long stroke descending to the right from an apex, crossed near the top by a shorter stroke descending to the left.
The same character; the catalogue records the letter itself and this its use as a physical quantity.
Wavelength and frequency are related by the wave speed.