Can A>B Be Determined by A-B>0 for Matrices?

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In summary, we can compare matrices using the notation A>B if A-B is positive definite. This notation allows for a strict partial ordering on the set of N x N matrices. Additionally, we can define A>=B if A-B is positive semidefinite. The transitivity axiom of ordering is satisfied in this notation as well as the other axioms.
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matqkks
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Can we compare matrices?
If A-B>0 is positive definite, can we say A>B?
 
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matqkks said:
Can we compare matrices?
If A-B>0 is positive definite, can we say A>B?
Yes, this is valid notation. This definition of ##>## gives us a strict partial ordering on the set of ##N\times N## matrices. Similarly, you can define ##A \geq B## if ##A - B## is positive semidefinite.

Note that if ##A > B## and ##B > C##, then ##A - B## and ##B - C## are positive definite, and ##A - C = (A - B) + (B - C)##. As the sum of two positive definite matrices is positive definite, this shows that the transitivity axiom of (partial or strict) ordering is satisfied. The other axioms are even easier to check.
 

FAQ: Can A>B Be Determined by A-B>0 for Matrices?

What is the difference between A-B>0 and A>B?

Both A-B>0 and A>B are comparisons between two matrices, but they have different meanings. A-B>0 means that the elements in matrix B are all smaller than the corresponding elements in matrix A. On the other hand, A>B means that all elements in matrix A are greater than the corresponding elements in matrix B.

Can A-B>0 and A>B be true at the same time?

No, A-B>0 and A>B cannot be true at the same time. If A-B>0 is true, it means that the elements in matrix B are smaller than those in matrix A, which contradicts A>B where the elements in matrix A must be greater than those in matrix B.

What is the significance of comparing matrices?

Comparing matrices allows us to determine the relationship and differences between two sets of data. It can help us identify patterns, similarities, and differences between different matrices.

Are there any limitations to comparing matrices?

Yes, there are limitations to comparing matrices. The matrices must have the same dimensions in order to be compared. Additionally, the matrices must contain numerical data, as comparisons cannot be made with non-numerical data.

How can comparing matrices be useful in scientific research?

Comparing matrices can be useful in scientific research in various ways. It can help identify trends and patterns in data, aid in data analysis, and provide insights into relationships between different variables. It can also aid in making predictions and drawing conclusions based on the data being compared.

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