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Operator space bounded operators

The set of bounded operators acting in a Hilbert space form a normed linear space. The norm is given by the bound on the operator... [Pg.246]

It is worth noting here that in a finite-dimensional space any linear operator is bounded. All of the linear bounded operators from X into Y constitute what is called a normed vector space, since the norm j4 of an operator A satisfies all of the axioms of the norm ... [Pg.42]

Linear bounded operators in a real Hilbert space. Let H he a real Hilbert space equipped with an inner product x,y) and associated norm II X II = (x, x). We consider bounded linear operators defined on the space... [Pg.43]

Theorem 4 Let A he a linear bounded operator in Hilbert space H, V[A) = H. In order that the operator A possess an inverse operator A with the domain V(A ) = H, it is necessary and sufficient the existence of a constant 5 > 0 such that for all x H the following inequalities hold ... [Pg.47]

The formulas of Appendix A are easily transformed to time-dependent forms via the Fourier-Laplace transform. For the purpose of upcoming extensions to the nonself adjoint case, we introduce the self-adjoint Hamiltonian H = FT = Htt. Furthermore the function 0 considered above is said to belong to the domain of the operator H, i.e.,

self-adjoint problems D(W) = D(H) and for bounded operators, the range R(H) and the domain D(H) are identical with the full Hilbert space however, in general applications they will differ as we will see later. [Pg.88]

If, further, T is a linear operator defined on the L2 space , one says that an element F = F(X) belongs to the domain D(T) of the operator T, if both T and its image TT belong to L2 the set T P is then referred to as the range of the operator T. It should be observed that a bounded operator T as a rule has the entire Hilbert space as its domain—or may be extended to achieve this property—whereas an unbounded operator T has a more restricted domain. In the latter case, we will let the symbol C(T) denote the complement to the domain D(T) with respect to the Hilbert space. A function F = (X) is hence an element of C(T), if it belongs to L2, whereas this is not true for its image 7 F. [Pg.100]

If u is a bounded operator, it may be defined over the entire one-particle Hilbert space, which we will assume to be of type L2, so that... [Pg.199]

In conclusion note that in a finite dimensional space any linear operator is bounded and continuous. [Pg.536]

A superoperator G defined on the Hilbert-Schmidt operator space is said to be bounded, if it satisfies the inequality... [Pg.319]

The relative calculational efficiency of EOM-Green s function methods and conventional configuration interaction methods is a difficult matter to assess, since it is intimately bound to the question of optimization of computer codes. Our major emphasis has been on determining the requirements for an accurate and reliable EOM theory. Of necessity, the program optimization has to an extent taken a back seat to the constant changes introduced in the theory in the course of this work. However, the demonstrated ability to obtain accurate results for the simple ionization potentials of small molecules with very small primary operator spaces bodes well for the EOM method. [Pg.63]

The discrete variable method can be interpreted as a kind of hybrid method Localized space but still a globally defined basis function. In the finite element methods not only the space will be discretized into local elements, the approximation polynomials are in addition only defined on this local element. Therefore we are able to change not only the size of the finite elements but in addition the locally selected basis in type and order. Usually only the size of the finite elements are changed but not the order or type of the polynomial interpolation function. Finite element techniques can be applied to any differential equation, not necessarily of Schrodinger-type. In the coordinate frame the kinetic energy is a simple differential operator and the potential operator a multiplication operator. In the momentum frame the coordinate operator would become a differential operator and hence due to the potential function it is not simple to find an alternative description in momentum space. Therefore finite element techniques are usually formulated in coordinate space. As bound states x xp) = tp x) are normalizable we could always find a left and right border, (x , Xb), in space beyond which the wave-functions effectively vanishes ... [Pg.306]

The Banach space [29] of bounded operators acting in Ffp is denoted and is spanned by a second quantized operator basis... [Pg.111]

It says that a setM of bounded operators acts non-degenerative on the Hilbert spaces H, if ... [Pg.379]

Let // be a Hilbert space. For each subset M from L(H), it will be considered its switched, M the set of bounded operators from H which switches with each operator from M. Therefore, M is a Banach algebra of operators which includes the identical element 1. [Pg.384]

For space environments for humans to become feasible, further research and development must take place in three main areas fife-support systems and shielding, types of space-bound habitats, and resources to sustain habitat populations. Given the vast number of possibilities within these scenarios, there are many considerations that will take precedence over others as humankind progresses toward a more developed future in space. For example, the operating conditions, power resources needs, and amenities aboard a habitat built for long-term, near-Earth orbit will be very different from those for a round-trip to the Moon or Mars. Despite these differences, there are many other areas in which research and development could uncover certain universally applicable materials and techniques. [Pg.1700]

The bounding box of inputs obtained using the above formulation represents idealistic values of the required bounds of the inputs. In other words, these bounds would be sufficient only for the optimal controller to cover the entire operating space. A feedback controller would require larger input ranges in order to accomplish the same task within the desired response time, ti. [Pg.120]

We can now proceed to the generation of conformations. First, random values are assigne to all the interatomic distances between the upper and lower bounds to give a trial distam matrix. This distance matrix is now subjected to a process called embedding, in which tl distance space representation of the conformation is converted to a set of atomic Cartesic coordinates by performing a series of matrix operations. We calculate the metric matrix, each of whose elements (i, j) is equal to the scalar product of the vectors from the orig to atoms i and j ... [Pg.485]

Theorem 1.16. Let V be a reflexive separable Banach space, and K be a closed convex subset in V. Assume that an operator A V V is pseudomonotonous, and A is coercive or K is bounded. Then the inequality (1.86) has a solution. [Pg.33]


See other pages where Operator space bounded operators is mentioned: [Pg.133]    [Pg.140]    [Pg.133]    [Pg.140]    [Pg.199]    [Pg.343]    [Pg.328]    [Pg.156]    [Pg.155]    [Pg.162]    [Pg.2775]    [Pg.2790]    [Pg.244]    [Pg.73]    [Pg.108]    [Pg.122]    [Pg.329]    [Pg.444]    [Pg.79]    [Pg.191]    [Pg.91]    [Pg.105]    [Pg.261]    [Pg.2860]   
See also in sourсe #XX -- [ Pg.246 ]




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