43 research outputs found
Some Algebraic Symmetries of (2,2)-Supersymmetric Systems
The Hilbert spaces of supersymmetric systems admit symmetries which are often
related to the topology and geometry of the (target) field-space. Here, we
study certain (2,2)-supersymmetric systems in 2-dimensional spacetime which are
closely related to superstring models. They all turn out to posess some
hitherto unexploited and geometrically and topologically unobstructed
symmetries, providing new tools for studying the topology and geometry of
superstring target spacetimes, and so the dynamics of the effective field
theory in these.Comment: plain TeX (needs "harvmac"), 9 pages, 2 references added & typos
correcte
Quantum Mechanics is Either Non-Linear Or Non-Introspective
The measurement conundrum seems to have plagued quantum mechanics for so long
that impressions of an inconsistency amongst its axioms have spawned.
A demonstration that such purported inconsistency is fictitious may then be
in order and is presented here.
An exclusion principle of sorts emerges, stating that quantum mechanics
cannot be simultaneously linear and introspective (self-observing).Comment: 8 pages, plain TeX + harvmac.tex + included macro
Yang-Mills and Supersymmetry Covariance Must Coexist
Supersymmetry and Yang-Mills type gauge invariance are two of the essential
properties of most, and possibly the most important models in fundamental
physics. Supersymmetry is nearly trivial to prove in the (traditionally
gauge-noncovariant) superfield formalism, whereas the gauge-covariant formalism
makes gauge invariance manifest. In 3+1-dimensions, the transformation from one
into the other is elementary and essentially unique. By contrast, this
transformation turns out to be impossible in the most general 1+1-dimensional
case. In fact, only the (manifestly) gauge- and supersymmetry-covariant
formalism guarantees both universal gauge-invariance and supersymmetry.Comment: 17 pages, TeX+harvma
Advanced Concepts in Particle and Field Theory
Uniting the usually distinct areas of particle physics and quantum field theory, gravity and general relativity, this expansive and comprehensive textbook of fundamental and theoretical physics describes the quest to consolidate the elementary particles that are the basic building blocks of nature. Designed for advanced undergraduates and graduate students and abounding in worked examples and detailed derivations, as well as historical anecdotes and philosophical and methodological perspectives, this textbook provides students with a unified understanding of all matter at the fundamental level. Topics range from gauge principles, particle decay and scattering cross-sections, the Higgs mechanism and mass generation, to spacetime geometries and supersymmetry. By combining historically separate areas of study and presenting them in a logically consistent manner, students will appreciate the underlying similarities and conceptual connections across these fields. This title, first published in 2015, has been reissued as an Open Access publication
Advanced Concepts in Particle and Field Theory
Uniting the usually distinct areas of particle physics and quantum field theory, gravity and general relativity, this expansive and comprehensive textbook of fundamental and theoretical physics describes the quest to consolidate the elementary particles that are the basic building blocks of nature. Designed for advanced undergraduates and graduate students and abounding in worked examples and detailed derivations, as well as historical anecdotes and philosophical and methodological perspectives, this textbook provides students with a unified understanding of all matter at the fundamental level. Topics range from gauge principles, particle decay and scattering cross-sections, the Higgs mechanism and mass generation, to spacetime geometries and supersymmetry. By combining historically separate areas of study and presenting them in a logically consistent manner, students will appreciate the underlying similarities and conceptual connections across these fields. This title, first published in 2015, has been reissued as an Open Access publication
String Theory Bounds on the Cosmological Constant, the Higgs mass, and the Quark and Lepton Masses
We elaborate on the new understanding of the cosmological constant and the
gauge hierarchy problems in the context of string theory in its metastring
formulation, based on the concepts of modular spacetime and Born geometry. The
interplay of phase space (and Born geometry), the Bekenstein bound, the mixing
between ultraviolet (UV) and infrared (IR) physics and modular invariance in
string theory is emphasized. This new viewpoint is fundamentally rooted in
quantum contextuality and not in statistical observer bias (anthropic
principle). We also discuss the extension of this point of view to the problem
of masses of quarks and leptons and their respective mixing matrices.Comment: 31 pages, minor edits, reference adde
On de Sitter Spacetime and String Theory
We review various aspects of de Sitter spacetime in string theory: its status
as an effective field theory spacetime solution, its relation to the vacuum
energy problem in string theory, its (global) holographic definition in terms
of two entangled and non-canonical conformal field theories, as well as a
realization of a realistic de Sitter universe endowed with the observed visible
matter and the necessary dark sector in order to reproduce the realistic
cosmological structure. In particular, based on the new insight regarding the
cosmological constant problem in string theory, we argue that in a doubled,
T-duality-symmetric, phase-space-like and non-commutative generalized-geometric
formulation, string theory can naturally lead to a small and positive
cosmological constant that is radiatively stable and technically natural. Such
a formulation is fundamentally based on a quantum spacetime, but in an
effective spacetime description of this general formulation of string theory,
the curvature of the dual spacetime is the cosmological constant of the
observed spacetime, while the size of the dual spacetime is the gravitational
constant of the same observed spacetime. Also, the three scales associated with
intrinsic non-commutativity of string theory, the cosmological constant scale
and the Planck scale, as well as the Higgs scale, can be arranged to satisfy
various seesaw-like formulae. Along the way, we show that these new features of
string theory can be implemented in a particular deformation of
cosmic-string-like models.Comment: 116 pages, 4 figure
A Q
Within each supermultiplet in the standard literature, supersymmetry relates its bosonic and fermionic component fields in a fixed way, particularly to the selected supermultiplet. Herein, we describe supermultiplets wherein a continuously variable “tuning parameter” modifies the supersymmetry transformations, effectively parametrizing a novel “Q-continuum” of distinct finite-dimensional off-shell supermultiplets, which may be probed already with bilinear Lagrangians that couple to each other and to external magnetic fields, two or more of these continuously many supermultiplets, each “tuned” differently. The dependence on the tuning parameters cannot be removed by any field redefinition, rendering this “Q-moduli space” observable