28.12.2013 Views

Studies in Rings generalised Unique Factorisation Rings

Studies in Rings generalised Unique Factorisation Rings

Studies in Rings generalised Unique Factorisation Rings

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

-6-<br />

If both conditions hold, R is said to be<br />

Noetherian.<br />

Example 1 0 6 .<br />

It is easy to observe that the 2 x 2 matrices of<br />

the form [~~<br />

where a € Z and b,c E. Q make a r<strong>in</strong>g which<br />

) 1<br />

is right Noethcrian but not left Noetherian.<br />

Proposition 1 07.<br />

Let B be a submodule of A. Then A is Noetherian if<br />

and<br />

only if 8 and A/S are both Noetherian.<br />

Corollary 1.8.<br />

Noetherian.<br />

Any f<strong>in</strong>ite direct sum of Noetherian modules is<br />

Corollary 1.9.<br />

If R is a Noetherian r<strong>in</strong>g, all f<strong>in</strong>itely generated<br />

right R-modules are Noetheriano<br />

Def<strong>in</strong>ition 1010.<br />

Given a r<strong>in</strong>g R and a positive <strong>in</strong>teger n, we use<br />

M (R) to denote the r<strong>in</strong>g of all n x n matrices over R.<br />

n<br />

The standard n x n matrix units <strong>in</strong> M (R) are the matrices<br />

n<br />

e .. (for i,j = 1,2, •.. ,n) such that e .. has 1 as the i_jth<br />

1) 1J<br />

entry and 0 elsewhere.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!