1,909 research outputs found

### Looking beyond the Thermal Horizon: Hidden Symmetries in Chiral Models

In thermal states of chiral theories, as recently investigated by H.-J.
Borchers and J. Yngvason, there exists a rich group of hidden symmetries. Here
we show that this leads to a radical converse of of the Hawking-Unruh
observation in the following sense. The algebraic commutant of the algebra
associated with a (heat bath) thermal chiral system can be used to reprocess
the thermal system into a ground state system on a larger algebra with a larger
localization space-time. This happens in such a way that the original system
appears as a kind of generalized Unruh restriction of the ground state sytem
and the thermal commutant as being transmutated into newly created ``virgin
space-time region'' behind a horizon. The related concepts of a ``chiral
conformal core'' and the possibility of a ``blow-up'' of the latter suggest
interesting ideas on localization of degrees of freedom with possible
repercussion on how to define quantum entropy of localized matter content in
Local Quantum Physics.Comment: 17 pages, tcilatex, still more typos removed and one reference
correcte

### Bondi-Metzner-Sachs symmetry, holography on null-surfaces and area proportionality of "light-slice" entropy

It is shown that certain kinds of behavior, which hitherto were expected to
be characteristic for classical gravity and quantum field theory in curved
spacetime, as the infinite dimensional Bondi-Metzner-Sachs symmetry, holography
on event horizons and an area proportionality of entropy, have in fact an
unnoticed presence in Minkowski QFT. This casts new light on the fundamental
question whether the volume propotionality of heat bath entropy and the
(logarithmically corrected) dimensionless area law obeyed by
localization-induced thermal behavior are different geometric parametrizations
which share a common primordeal algebraic origin. Strong arguments are
presented that these two different thermal manifestations can be directly
related, this is in fact the main aim of this paper. It will be demonstrated
that QFT beyond the Lagrangian quantization setting receives crucial new
impulses from holography onto horizons. The present paper is part of a project
aimed at elucidating the enormous physical range of "modular localization". The
latter does not only extend from standard Hamitonian heat bath thermal states
to thermal aspects of causal- or event- horizons addressed in this paper. It
also includes the recent understanding of the crossing property of formfactors
whose intriguing similarity with thermal properties was, although sometimes
noticed, only sufficiently understood in the modular llocalization setting.Comment: 42 pages, changes, addition of new results and new references, in
this form the paper will appear in Foundations of Physic

### The Pivotal Role of Causality in Local Quantum Physics

In this article an attempt is made to present very recent conceptual and
computational developments in QFT as new manifestations of old and well
establihed physical principles. The vehicle for converting the
quantum-algebraic aspects of local quantum physics into more classical
geometric structures is the modular theory of Tomita. As the above named
laureate to whom I have dedicated has shown together with his collaborator for
the first time in sufficient generality, its use in physics goes through
Einstein causality. This line of research recently gained momentum when it was
realized that it is not only of structural and conceptual innovative power (see
section 4), but also promises to be a new computational road into
nonperturbative QFT (section 5) which, picturesquely speaking, enters the
subject on the extreme opposite (noncommutative) side.Comment: This is a updated version which has been submitted to Journal of
Physics A, tcilatex 62 pages. Adress: Institut fuer Theoretische Physik
FU-Berlin, Arnimallee 14, 14195 Berlin presently CBPF, Rua Dr. Xavier Sigaud
150, 22290-180 Rio de Janeiro, Brazi

### Mutually local fields from form factors

We compare two different methods of computing form factors. One is the well
established procedure of solving the form factor consistency equations and the
other is to represent the field content as well as the particle creation
operators in terms of fermionic Fock operators. We compute the corresponding
matrix elements for the complex free fermion and the Federbush model. The
matrix elements only satisfy the form factor consistency equations involving
anyonic factors of local commutativity when the corresponding operators are
local. We carry out the ultraviolet limit, analyze the momentum space cluster
properties and demonstrate how the Federbush model can be obtained from the
$SU(3)_3$-homogeneous sine-Gordon model. We propose a new class of Lagrangians
which constitute a generalization of the Federbush model in a Lie algebraic
fashion. For these models we evaluate the associated scattering matrices from
first principles, which can alternatively also be obtained in a certain limit
of the homogeneous sine-Gordon models.Comment: 16 pages Late

### Causality and dispersion relations and the role of the S-matrix in the ongoing research

The adaptation of the Kramers-Kronig dispersion relations to the causal
localization structure of QFT led to an important project in particle physics,
the only one with a successful closure. The same cannot be said about the
subsequent attempts to formulate particle physics as a pure S-matrix project.
The feasibility of a pure S-matrix approach are critically analyzed and their
serious shortcomings are highlighted. Whereas the conceptual/mathematical
demands of renormalized perturbation theory are modest and misunderstandings
could easily be corrected, the correct understanding about the origin of the
crossing property requires the use of the mathematical theory of modular
localization and its relation to the thermal KMS condition. These new concepts,
which combine localization, vacuum polarization and thermal properties under
the roof of modular theory, will be explained and their potential use in a new
constructive (nonperturbative) approach to QFT will be indicated. The S-matrix
still plays a predominant role but, different from Heisenberg's and
Mandelstam's proposals, the new project is not a pure S-matrix approach. The
S-matrix plays a new role as a "relative modular invariant"..Comment: 47 pages expansion of arguments and addition of references,
corrections of misprints and bad formulation

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