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Chapter 4 Hilbert Space. 4.1 Inner product space. Inner product. E : complex vector space. is called an inner product on E if. Inner product space. E : complex vector space. Show in next some pages. is an inner product on E. With such inner product E is called.
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Inner product E : complex vector space is called an inner product on E if
Inner product space E : complex vector space Show in next some pages is an inner product on E With such inner product E is called inner product space. If we write ,then is a norm on E and hence E is a normed vector space.
Schwarz Inequality E is an inner product space
Triangular Inequality for ∥ .∥ E is an inner product space
Exercise 1.1 (i) For Show that and hence is absolutely convergent
Exercise 1.1 (ii) Show that is complete
Hilbert space An inner product space E is called Hilbert space if is complete is a Hilbert space of which
Exercise 1.2 Define real inner product space and real Hilbert space.
Theorem 2.1 p.1 E: inner product space M: complete convex subset of E Let then the following are equivalent
Theorem 2.1 p.2 (1) (2) Furthermore there is a unique satisfing (1) and (2).
Projection from E onto M The map defined by tx=y, where y is the unique element in M which satisfies (1) of Thm 1 is called the projection from E onto M. and is denoted by
Corollary 2.1 Let M be a closed convex subset of a Hilbert space E, then has the following properties:
Convex Cone A convex set M in a vector space is called a convex cone if
Exercise 2.2 (i) Let M be a closed convex cone in a Hilbert space E and let Put Show that I being the identity map of E.
Exercise 2.2 (ii) ( t is positive homogeneous)
Exercise 2.2 (v) conversely if then
Exercise 2.2 (vi) In the remaining exercise, suppose that M is a closed vector subspace of E. Show that
Exercise 2.2 (vii) both t and s are continuous and linear
Exercise 2.2 (x) tx and sx are the unique elements such that x=y+z