Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Representations unitary, definition

Let us briefly mention some formal aspects of the above-introduced formalism, which have been discussed in detail by Blaizot and Marshalek [218]. First, it is noted that the both the Schwinger and the Holstein-Primakoff representations are not unitary transformations in the usual sense. Nevertheless, a transformation may be defined in terms of a formal mapping operator acting in the fermionic-bosonic product Hilbert space. Furthermore, the interrelation of the Schwinger representation and the Holstein-Primakoff representation has been investigated in the context of quantization of time-dependent self-consistent fields. It has been shown that the representations are related to each other by a nonunitary transformation. This lack of unitarity is a consequence of the nonexistence of a unitary polar decomposition of the creation and annihilation operators a and at [221] and the resulting difficulties in the definition of a proper phase operator in quantum optics [222]. [Pg.304]

The essential concept in the definition of the CDF is the use of time-dependent basis states in place of stationary basis states in the representation of the time evolution of a system, with the constraint that both sets of states are orthonormal. Consider a complete set of orthonormal stationary states S and a complete set of orthonormal time-dependent basis states D t) related by the unitary transformation U t) ... [Pg.54]

In all the important quantum mechanical applications, the representations are unitary. Recall the unitary group U (V) from Definition 4.2. [Pg.132]

We start by defining the projective unitary representations. Recall the unitary group ZT (V) of a complex scalar product space V from Definition 4.2. The following definition is an analog of Definition 4.11. [Pg.318]

Definition 10.7 Suppose G is a group and V is a complex scalar product space. Then the triple G, V, p) is called a projective unitary representation if and only if p is a group homomorphism from G to PIT (V). [Pg.319]

Definition 10.8 Suppose G is a group, V is a complex scalar product space and p. G PU (V) is a projective unitary representation. We say that p is irreducible if the only subspace W of V such that [VT] is invariant under p is V itself. [Pg.321]

We begin by reiterating the definition of a PR and listing some conventions regarding PFs. A projective unitary representation of a group G = g, of dimension g is a set of matrices that satisfy the relations... [Pg.234]

In summary, the model allows for two types of interactions between the mirror spaces, the weak kinematical perturbation and the adiabatic and sudden limits equivalent to Eq. (17) or Eqs. (29)-(34). The overwhelming rate of particles over antiparticles in the Universe is inferred in this picture once the particular particle state has been selected. The Minkowski metric of the special theory of relativity is represented here by a non-positive definite metric, Eq. (8), bringing about a quantum model with a complex symmetric ansatz. Although the latter permits general symmetry violations, it is nevertheless surprising that fundamental transformations between complex symmetric representations and canonical forms come out unitary. [Pg.131]

Obviously, is simply 4 (Z = 0) and is by definition time independent. Equation (2.62) is a unitary transformation on the wavefunctions and the operators at time t. The original representation in which the wavefunctions are time dependent while the operators are not, is transformed to another representation in which the operators depend on time while the wavefunctions do not. The original fonnulation is referred to as the Schrodinger representation, while the one obtained using (2.62) is called the Heisenberg representation. We sometimes use the subscript S to emphasize the Schrodinger representation nature of a wavefunction or an operator, that is. [Pg.76]

Fig. 7 Comparative representation of the progress curves for the CIPAH ligands of Fig. 6 bound to human breast cancer MCF-7 cells, employing the recorded EROD/human-QRAR reactivity-activity information from Table 10 into logistic chemical-biological interactions modeled by Eq. (89), on the mapped unitary time scale of Eq. (15), for each index/quantum chemical method considered and for an EROD EC50 = 34.696 pM norm parameter as computed with algebraic definition (12b) and the EROD/human data of Table 5... Fig. 7 Comparative representation of the progress curves for the CIPAH ligands of Fig. 6 bound to human breast cancer MCF-7 cells, employing the recorded EROD/human-QRAR reactivity-activity information from Table 10 into logistic chemical-biological interactions modeled by Eq. (89), on the mapped unitary time scale of Eq. (15), for each index/quantum chemical method considered and for an EROD EC50 = 34.696 pM norm parameter as computed with algebraic definition (12b) and the EROD/human data of Table 5...
Remembering that the characters for are surrogates for two rows of characters, the real value of n for the representation is half of the calculated one (left in brackets to remind us that it was derived from the surrogate characters). Thus, = A + E and not A -F 2 . Indeed, this result is consistent with the overall dimensionality of the RR. The dimension of Fj is 3 (because that is its character for the identity operation). Thus, the sum of the dimensions of the IRRs comprising Fjj must also equal 3. The result A -F is consistent with this rule, because A representations are always unitary and (by definition) the representation has a dimension of 2. Had we forgotten to divide the results for by two in our table, we would have erroneously obtained the result A -F 2 , which has a total dimension of 5 and is inconsistent with the dimensionality of our original RR. [Pg.220]

Here we describe the basic ingredients of the AJL algorithm which are 1) The definition of the Kauffman bracket, 2) the definition of the Jones polynomial in terms of the Kauffman bracket, 3) the representation of the Kauffman bracket as the Markov trace of an unitary representation of the braid algebra via the Temperley-Lieb algebra 4) the quantum compilation of the unitary braid representation and, 5) the Hadamard test. [Pg.201]

The definition and properties of such operators are presented here.in general form. In the text they have been used mainly for unitary representations, in which case the matrix elements in the contragredient representation (p. 538) ate D R j =... [Pg.541]

For the real unitary matrix representations we have been considering, the matrix of the inverse transformation is obtained from the original matrix by simply interchanging rows and columns. By definition, therefore... [Pg.374]


See other pages where Representations unitary, definition is mentioned: [Pg.132]    [Pg.170]    [Pg.102]    [Pg.281]    [Pg.425]    [Pg.34]    [Pg.20]    [Pg.9]    [Pg.258]    [Pg.6]    [Pg.45]    [Pg.525]   
See also in sourсe #XX -- [ Pg.87 ]




SEARCH



Representation definition

© 2024 chempedia.info