# Matrix consisting of the matrices [duplicate]

I need Dirac Matrix in my work. They consists of PauliMatrix and ZeroMatrix, which is:

ZeroMatrix:=IdentityMatrix-IdentityMatrix


I define Dirac Matrix as:

gamma = ({{PauliMatrix, ZeroMatrix}, {ZeroMatrix, -PauliMatrix}}) // MatrixForm;


I got such result: But I need something else: I need a monolithic table, does not consist of individual blocks. How can I get it? (I need something universal, because I need to use it to construct 4 gamma matrices and spinors).

• In fact this is a special case of How to Flatten Array of Arrays of the highest order in a simple way? – Artes Aug 13 '14 at 18:58
• Array[0 &, {2, 2}] would be better than IdentityMatrix - IdentityMatrix :) – Öskå Aug 13 '14 at 19:00
• @Artes Why not vote to close? Also a duplicate of (761) I believe. – Mr.Wizard Aug 13 '14 at 21:05
• @Mr.Wizard I've done it, but since I've been one of the most frequent reviewers I expected others to start closing. – Artes Aug 13 '14 at 21:26
• @Artes There is no obligation but as it takes no longer to vote to close than it does to comment why not vote? – Mr.Wizard Aug 13 '14 at 21:27

## 1 Answer

ArrayFlatten[] takes zeroes as a representation of a zero square matrix:

gamma = {{PauliMatrix, 0}, {0, -PauliMatrix}}
ArrayFlatten[gamma]


Which gives {{1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, -1, 0}, {0, 0, 0, -1}}