Matrix Inequality: Is BTB <= B1TB1?

  • Context: Graduate 
  • Thread starter Thread starter hayu601
  • Start date Start date
  • Tags Tags
    Inequality Matrix
Click For Summary
SUMMARY

The discussion centers on the matrix inequality (A+B)T(A+B) <= (A+B1)T(A+B1) and its implications for the relationship between BTB and B1TB1. Participants analyze the expansion of both sides, noting that A^T A cancels out, which leads to a comparison of the remaining terms. The conclusion drawn is that the inequality BTB <= B1TB1 does not necessarily hold without additional constraints on matrices B and B1.

PREREQUISITES
  • Understanding of matrix algebra and properties of transposition
  • Familiarity with quadratic forms in linear algebra
  • Knowledge of matrix inequalities and their implications
  • Experience with symbolic manipulation of algebraic expressions
NEXT STEPS
  • Study the properties of symmetric matrices and their implications on inequalities
  • Learn about the conditions under which matrix inequalities hold
  • Explore the concept of positive definiteness in relation to matrix inequalities
  • Investigate examples of matrix inequalities in optimization problems
USEFUL FOR

Mathematicians, researchers in linear algebra, and students studying optimization and matrix theory will benefit from this discussion.

hayu601
Messages
7
Reaction score
0
I am puzzled about this simple case,

Suppose we have (A+B)T(A+B) <= (A+B1)T(A+B1),

Can we say something about the relation between BTB and B1TB1?

For example, is it correct if I say BTB <= B1TB1?
 
Physics news on Phys.org
Expand all the terms on each side. You'll see that
A^T A
cancels, leaving three additional terms on each side. Does your hypothesis follow?
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
3K
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 33 ·
2
Replies
33
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 12 ·
Replies
12
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K