upsilon
Upsilon is the 20th letter of the Greek alphabet, written uppercase Υ and lowercase υ. It is the origin of the Latin letter Y and is widely used as a symbol in science and mathematics. The name upsilon derives from the ancient Greek word υψιλον (hypsilon), and the letter historically represented a close vowel that varied in pronunciation across dialects.
In classical Greek, upsilon represented a close front rounded vowel (/y/) or a close back (/u/) depending
In the system of Greek numerals, upsilon has the value 400. Its typographic forms include the standard
The letter has several prominent uses. In particle physics, Υ denotes the bottomonium meson family, with states