arXiv subjects

Bertfried Fauser

Publications and source records attributed to Bertfried Fauser.

45 records · Page 3Linked to original sources

arXiv1999

Isospin from Spin by Compositenes

We propose a new method to generate the internal isospin degree of freedom by non-local bound states. This can be seen as motivated by Bargmann-Wigner like considerations, which originated from local spin coupling. However, our approach is not of purely group theoretical origin, but emerges from a geometrical model. The rotational part of the Lorentz group can be seen to mutate into the internal iso-group under some additional assumptions. The bound states can thereafter be characterized by either a triple of spinors (ξ_1, ξ_2, η) or a pair of an average spinor and a ``gauge'' transformation (ϕ, R). Therefore, this triple can be considered to be an isospinor. Inducing the whole dynamics from the covariant gauge coupling we arrive at an isospin gauge theory and its Lagrangian formulation. Clifford algebraic methods, especially the Hestenes approach to the geometric meaning of spinors, are the most useful concepts for such a development. The method is not restricted to isospin, which served as an example only.

hep-th↗

arXiv1998

On the relation of Clifford-Lipschitz groups to q-symmetric groups

It can be shown that it is possible to find a representation of Hecke algebras within Clifford algebras of multivectors. These Clifford algebras possess a unique gradation and a possibly non-symmetric bilinear form. Hecke algebra representations can be classified, for non-generic q, by Young tableaux of the symmetric group due to the isomorphy of the group algebras for q ->1. Since spinors can be constructed as elements of minimal left (right) ideals obtained by the left (right) action on primitive idempotents, we are able to construct q-spinors from q-Young operators corresponding to the appropriate symmetry type. It turns out that an anti-symmetric part in the Clifford bilinear form is necessary. q-deformed reflections (Hecke generators) can be obtained only for even multivector aggregates rendering this symmetry a composite one. In this construction one is able to deform spin groups only, though not pin groups. The method is closely related to a projective interpretation.

math.QA↗

arXiv1997

On an easy transition from operator dynamics to generating functionals by Clifford algebras

Clifford geometric algebras of multivectors are treated in detail. These algebras are build over a graded space and exhibit a grading or multivector structure. The careful study of the endomorphisms of this space makes it clear, that opposite Clifford algebras have to be used also. Based on this mathematics, we give a fully Clifford algebraic account on generating functionals, which is thereby geometric. The field operators are shown to be Clifford and opposite Clifford maps. This picture relying on geometry does not need positivity in principle. Furthermore, we propose a transition from operator dynamics to corresponding generating functionals, which is based on the algebraic techniques. As a calculational benefit, this transition is considerable short compared to standard ones. The transition is not injective (unique) and depends additionally on the choice of an ordering. We obtain a direct and constructive connection between orderings and the explicit form of the functional Hamiltonian. These orderings depend on the propagator of the theory and thus on the ground state. This is invisible in path integral formulations. The method is demonstrated within two examples, a non-linear spinor field theory and spinor QED. Antisymmetrized and normal-ordered functional equations are derived in both cases.

hep-th↗

arXiv1997

Hecke algebras as subalgebras of Clifford geometric algebras of multivectors

Clifford geometric algebras of multivectors are introduced which exhibit a bilinear form which is not necessarily symmetric. Looking at a subset of bi-vectors in CL(K^{2n},B), we proof that theses elements generate the Hecke algebra H_{K}(n+1,q) if the bilinear form B is chosen appropriately. This shows, that q-quantization can be generated by Clifford multivector objects which describe usually composite entities. This contrasts current approaches which give deformed versions of Clifford algebras by deforming the one-vector variables. Our example shows, that it is not evident from a mathematical point of view, that q-deformation is in any sense more elementary than the undeformed structure.

q-alg↗

arXiv1996

Vertex functions and generalized normal-ordering by triple systems in non-linear spinor field models

Triple systems are closely related to Yang-Baxter symmetries. Utilizing a non-parameter-dependent triple product, we derive the BCS interaction. The enlargement of the notion of symmetry leads in some sense to a regular vertex function. The connection to the effect of running coupling constants is outlined, which leads to the recently discussed anisotropic effective local interactions. Furthermore, a discussion of the physical nature of q-symmetries is given.

hep-th↗

arXiv1996

Dirac theory from a field theoretic point of view

Several complications arise in quantum field theory because of the infinite many degrees of freedom. However, the distinction between one-particle and many-particle effects -- mainly induced by the vacuum -- is not clear up to now. A field theoretic picture of the one-particle Dirac theory is developed in order to explore such questions. Main emphasis is laid on the injection of Grassmann's algebra into the endomorphism Clifford algebra built over it. The obtained ``field theoretic'' functional equation behaves in a very unusual way. New methods to handle Dirac and QFT are given.

hep-th↗

arXiv1995

Positronium as an example of algebraic composite calculations

The functional quantum field theory, developed by Stumpf, provides the possibility to derive the quantum dynamics of a positronium gas from Coulomb interacting electrons and positrons. By this example, the method will be brought in a Clifford algebraic light, through identifying the functional space with an infinite dimensional Euclidean Clifford algebra.

hep-th↗

arXiv1995

Clifford Algebraic Remark on the Mandelbrot Set of Two--Component Number Systems

We investigate with the help of Clifford algebraic methods the Mandelbrot set over arbitrary two-component number systems. The complex numbers are regarded as operator spinors in D\times spin(2) resp. spin(2). The thereby induced (pseudo) normforms and traces are not the usual ones. A multi quadratic set is obtained in the hyperbolic case contrary to [1]. In the hyperbolic case a breakdown of this simple dynamics takes place.

hep-th↗

arXiv1995

Vertex Normalordering as a Consequence of Nonsymmetric Bilinearforms in Clifford Algebras

We consider Clifford algebras with nonsymmetric bilinear forms, which are isomorphic to the standard symmetric ones, but not equal. Observing, that the content of physical theories is dependent on the injection $\oplus^n\bigwedge \V^{(n)}\to CL({\cal V},Q)$ one has to transform to the standard construction. The injection is of course dependent on the antisymmetric part of the bilinear form. This process results in the appropriate vertex normalordering terms, which are now obtained from the theory itself and not added ad hoc via a regularization argument.

hep-th↗