1,365 research outputs found
Asking Questions that Matter … Asking Questions of Value
Excerpt: When I first became involved formally in scholarship of teaching and learning, it was the result of frustration and surprise tempered by high expectations and hope. I was teaching in a school of liberal studies that used program portfolios as an intellectual organizing feature and culminating assessment (self and otherwise). Students were to use this portfolio (physical, not online) to collect and reflect on work they accomplished during their time in the program. But in teaching the senior synthesis course, wherein students were to “go meta” with the portfolio and reflect on their entire undergraduate experience, I learned that virtually all of them treated the portfolio not as..
Infrared Dynamics of a Large N QCD Model, the Massless String Sector and Mesonic Spectra
A consistency check for any UV complete model for large N QCD should be,
among other things, the existence of a well-defined vector and scalar mesonic
spectra. In this paper, we use our UV complete model in type IIB string theory
to study the IR dynamics and use this to predict the mesonic spectra in the
dual type IIA side. The advantage of this approach is two-fold: not only will
this justify the consistency of the supergravity approach, but it will also
give us a way to compare the IR spectra and the model with the ones proposed
earlier by Sakai and Sugimoto. Interestingly, the spectra coming from the
massless stringy sector are independent of the UV physics, although the massive
string sector may pose certain subtleties regarding the UV contributions as
well as the mappings to actual QCD. Additionally, we find that a component of
the string landscape enters the picture: there are points in the landscape
where the spectra can be considerably improved over the existing results in the
literature. These points in the landscape in-turn also determine certain
background supergravity components and fix various pathologies that eventually
lead to a consistent low energy description of the theory.Comment: 47 pages, 7 pdf figures, 24 tables, JHEP format; Detailed mathematica
file of the computations is available on request; Version 2: Text elaborated,
typos corrected, a new appendix added to discuss the regimes of validity, and
a word in the abstract changed. Results unchanged. Final version to appear in
JHE
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