372 research outputs found
The Strength of Non-Perturbative Effects in Matrix Models and String Effective Lagrangians
We present a summary of the results of an explicit calculation of the
strength of non-perturbative interactions in matrix models and string effective
Lagrangians. These interactions are induced by single eigenvalue instantons in
the bosonic matrix model. A well defined approximation scheme is used to
obtain induced operators whose exact form we exhibit. We briefly discuss the
possibility that similar instantons in a supersymmetric version of the theory
may break supersymmetry dynamically.Comment: Latex document, 17 pages, preprint CERN-TH.7356/94, UPR-620
Supersymmetric Field Theory from Supermatrix Models
We show that the continuum limit of one-dimensional N=2 supersymmetric matrix
models can be described by a two-dimensional interacting field theory of a
massless boson and two chiral fermions. We interpret this field theory as a
two-dimensional N=1 supersymmetric theory of two chiral superfields, in which
one of the chiral superfields has a non-trivial vacuum expectation value.Comment: Latex document, 11 pages, preprint CERN-TH.7353/94, UPR-621
Twisted Sectors and Chern-Simons Terms in M-Theory Orbifolds
It is shown that the twisted sector spectrum, as well as the associated
Chern-Simons interactions, can be determined on M-theory orbifold fixed planes
that do not admit gravitational anomalies. This is demonstrated for the
seven-planes arising within the context of an explicit orbifold, although the results are completely general. Local
anomaly cancellation in this context is shown to require fractional anomaly
data that can only arise from a twisted sector on the seven-planes, thus
determining the twisted spectrum up to a small ambiguity. These results open
the door to the construction of arbitrary M-theory orbifolds, including those
containing fixed four-planes which are of phenomenological interest.Comment: 21 pages, LaTe
An M-Theory Perspective on Heterotic K3 Orbifold Compactifications
We analyze the structure of heterotic M-theory on K3 orbifolds by presenting
a comprehensive sequence of M-theoretic models constructed on the basis of
local anomaly cancellation. This is facilitated by extending the technology
developed in our previous papers to allow one to determine "twisted" sector
states in non-prime orbifolds. These methods should naturally generalize to
four-dimensional models, which are of potential phenomenological interest.Comment: 58 pages, LaTe
A BPS Interpretation of Shape Invariance
We show that shape invariance appears when a quantum mechanical model is
invariant under a centrally extended superalgebra endowed with an additional
symmetry generator, which we dub the shift operator. The familiar mathematical
and physical results of shape invariance then arise from the BPS structure
associated with this shift operator. The shift operator also ensures that there
is a one-to-one correspondence between the energy levels of such a model and
the energies of the BPS-saturating states. These findings thus provide a more
comprehensive algebraic setting for understanding shape invariance.Comment: 15 pages, 2 figures, LaTe
NetSci High: Bringing Agency to Diverse Teens Through the Science of Connected Systems
This paper follows NetSci High, a decade-long initiative to inspire teams of teenage researchers to develop, execute and disseminate original research in network science. The project introduced high school students to the computer-based analysis of networks, and instilled in the participants the habits of mind to deepen inquiry in connected systems and statistics, and to sustain interest in continuing to study and pursue careers in fields involving network analysis. Goals of NetSci High ranged from proximal learning outcomes (e.g., increasing high school student competencies in computing and improving student attitudes toward computing) to highly distal (e.g., preparing students for 21st century science), with an emphasis on doing real-world research into relevant and ambiguous problems through technologically-infused and highly collaborative projects and defending them to a clear (and sometimes potentially intimidating) audience. The cognitive goals of the project covered broad areas including analyzing, synthesizing, and visualizing quantitative data, and understanding modeling and network statistics. Attitudinal outcomes included improving attitudes toward the statistical study of networks, self-efficacy, and a sense of agency for continuing to pursue further involvement in college studies and careers
Effective Symmetries of the Minimal Supermultiplet of N = 8 Extended Worldline Supersymmetry
A minimal representation of the N = 8 extended worldline supersymmetry, known
as the `ultra-multiplet', is closely related to a family of supermultiplets
with the same, E(8) chromotopology. We catalogue their effective symmetries and
find a Spin(4) x Z(2) subgroup common to them all, which explains the
particular basis used in the original construction. We specify a constrained
superfield representation of the supermultiplets in the ultra-multiplet family,
and show that such a superfield representation in fact exists for all adinkraic
supermultiplets. We also exhibit the correspondences between these
supermultiplets, their Adinkras and the E(8) root lattice bases. Finally, we
construct quadratic Lagrangians that provide the standard kinetic terms and
afford a mixing of an even number of such supermultiplets controlled by a
coupling to an external 2-form of fluxes.Comment: 13 Figure
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