Mathematical scripts

If your journal does not give any advice, please follow the suggestions below.

  • Special care should be taken with mathematical scripts, especially subscripts and superscripts and differentiation between the letter “ell” and the figure one, and the letter “oh” and the figure zero.
  • It is important to differentiate between: K and k; X, x and x (multiplication); asterisks intended to appear when published as multiplication signs and those intended to remain as asterisks, etc.
  • In both displayed equations and in text, scalar variables must be in italics, with non-variable matter in upright type.
  • For simple fractions in the text, the solidus “/” should be used instead of a horizontal line, care being taken to insert parentheses where necessary to avoid ambiguity. Exceptions are the proper fractions available (e.g., ¼, ½, ¾).
  • The solidus is not generally used for units: m s-¹ not m/s, but note electrons/s, counts/channel, etc.
  • Displayed equations referred to in the text should be numbered serially ((1), (2), etc.) on the right-hand side. Short expressions not referred to by any number will usually be incorporated into the text.
  • The following styles are preferred: upright bold sans serif r for tensors, bold serif italic r for vectors, upright bold serif for matrices, and medium-face sloping serif r for scalar variables. In mathematical expressions, the use of “d” for differential should be made clear, and coded in roman, not italic.
  • Braces, brackets, and parentheses are used in the order { [( )] }, except where mathematical convention dictates otherwise (e.g., square brackets for commutators and anticommutators; braces for the exponent in exponentials).
  • For units and symbols, the SI system should be used. Where measurements are given in other systems, please insert conversions.