# What is this matrix operation/symbol?

What is this matrix operation/symbol, the $\langle 0 \rangle$ in this expression? $$\Large {\left(\mathrm{s}_{a1}^{\;\;\mathrm{T}}\right)^{\langle 0 \rangle}}^{\mathrm{T}}$$

I've looked around on the web and I really don't know a good resource for stuff like this.

I am coming across this symbol in a few places, I'm not sure what this means. I also don't remember this from my brief linear algebra course in college, at least in the exponentiation spot. Additionally, if someone does have a good resource or reference for all types of math symbols, it'd be greatly appreciated, thanks.

• I would assume it means a matrix or vector all of whose entries are $0$. Can you say more about the context in which you saw this expression? – Eric Wofsey Nov 28 '15 at 3:52
• I would say the same: all entries are zeros... – Dac0 Nov 28 '15 at 6:06
• Sure, it's a structural engineering application. The matrix Sa1 is 74x6, and holds values of snow loads for various regions of the US on sloped roofs. Also, it's eventually used in combination with wind loads in some manner. There are 24 different wind speeds, and 6 snow load parameters, and another wind zone parameter that has 3 possible values. So the matrix is really 3 24x6 matrices stacked on each other, with a row of 0s separating them. Each 24x6 corresponding to one of the wind zone categories, and then the 24 rows are the wind speed index and the 6 columns are the snow load index. – krb686 Nov 28 '15 at 12:42
• Additionally, this matrix is being setup this way for some display reasons, and I think because it later gets used in conjunction with separate wind matrices, because since the matrix itself is only concerned with snow loads, the rows of the matrix don't really matter, the values repeat down through the rows - ie, each column is constant. I think at the end something says: give me snow load(windspeed=10, snow category=2, windzone=2) + wind load(windspeed=10, snow category=2,windzone=2), even though windspeed/zone don't apply to the snow matrix, and snow cat doesn't apply to the wind matrix. – krb686 Nov 28 '15 at 12:48