6,296 research outputs found
Hidden symmetry of the quantum Calogero-Moser system
Hidden symmetry of the quantum Calogero-Moser system with the inverse-square
potential is explicitly demonstrated in algebraic sense. We find the underlying
algebra explaining the super-integrability phenomenon for this system.
Applications to related multi-variable Bessel functions are also discussed.Comment: 16 pages, latex, no figure
T-Branes and Geometry
T-branes are a non-abelian generalization of intersecting branes in which the
matrix of normal deformations is nilpotent along some subspace. In this paper
we study the geometric remnant of this open string data for six-dimensional
F-theory vacua. We show that in the dual M-theory / IIA compactification on a
smooth Calabi-Yau threefold X, the geometric remnant of T-brane data translates
to periods of the three-form potential valued in the intermediate Jacobian of
X. Starting from a smoothing of a singular Calabi-Yau, we show how to track
this data in singular limits using the theory of limiting mixed Hodge
structures, which in turn directly points to an emergent Hitchin-like system
coupled to defects. We argue that the physical data of an F-theory
compactification on a singular threefold involves specifying both a geometry as
well as the remnant of three-form potential moduli and flux which is localized
on the discriminant. We give examples of T-branes in compact F-theory models
with heterotic duals, and comment on the extension of our results to
four-dimensional vacua.Comment: v2: 80 pages, 2 figures, clarifications and references added, typos
correcte
Nilpotent Networks and 4D RG Flows
Starting from a general SCFT, we study the network of
SCFTs obtained from relevant deformations by nilpotent mass
parameters. We also study the case of flipper field deformations where the mass
parameters are promoted to a chiral superfield, with nilpotent vev. Nilpotent
elements of semi-simple algebras admit a partial ordering connected by a
corresponding directed graph. We find strong evidence that the resulting fixed
points are connected by a similar network of 4D RG flows. To illustrate these
general concepts, we also present a full list of nilpotent deformations in the
case of explicit SCFTs, including the case of a single
D3-brane probing a - or -type F-theory 7-brane, and 6D conformal
matter compactified on a , as described by a single M5-brane probing a
- or -type singularity. We also observe a number of numerical
coincidences of independent interest, including a collection of theories with
rational values for their conformal anomalies, as well as a surprisingly nearly
constant value for the ratio for the entire
network of flows associated with a given UV SCFT. The
submission also includes the full dataset of theories which
can be accessed with a companion script.Comment: v2: 73 pages, 12 figures, clarifications and references adde
Local Starbursts in a Cosmological Context
In this contribution I introduce some of the major issues that motivate the
conference, with an emphasis on how starbursts fit into the ``big picture''. I
begin by defining starbursts in several different ways, and discuss the merits
and limitations of these definitions. I will argue that the most physically
useful definition of a starburst is its ``intensity'' (star formation rate per
unit area). This is the most natural parameter to compare local starbursts with
physically similar galaxies at high redshift, and indeed I will argue that
local starbursts are unique laboratories to study the processes at work in the
early universe. I will describe how NASA's GALEX mission has uncovered a rare
population of close analogs to Lyman Break Galaxies in the local universe. I
will then compare local starbursts to the Lyman-Break and sub-mm galaxies high
redshift populations, and speculate that the multidimensional ``manifold'' of
starbursts near and far can be understood largely in terms of the
Schmidt/Kennicutt law and galaxy mass-metallicity relation. I will briefly
summarize he properties of starburst-driven galactic superwinds and their
possible implications for the evolution of galaxies and the IGM. These complex
multiphase flows are best studied in nearby starbursts, where we can study the
the hot X-ray gas that contains the bulk of the energy and newly produced
metals.Comment: Proceedings of the Conference "Starbursts: Fropm 30 Doradus to Lyman
Break Galaxies
T-Branes at the Limits of Geometry
Singular limits of 6D F-theory compactifications are often captured by
T-branes, namely a non-abelian configuration of intersecting 7-branes with a
nilpotent matrix of normal deformations. The long distance approximation of
such 7-branes is a Hitchin-like system in which simple and irregular poles
emerge at marked points of the geometry. When multiple matter fields localize
at the same point in the geometry, the associated Higgs field can exhibit
irregular behavior, namely poles of order greater than one. This provides a
geometric mechanism to engineer wild Higgs bundles. Physical constraints such
as anomaly cancellation and consistent coupling to gravity also limit the order
of such poles. Using this geometric formulation, we unify seemingly different
wild Hitchin systems in a single framework in which orders of poles become
adjustable parameters dictated by tuning gauge singlet moduli of the F-theory
model.Comment: v2: 65 pages, 6 figures, clarifications adde
The Footprint of F-theory at the LHC
Recent work has shown that compactifications of F-theory provide a
potentially attractive phenomenological scenario. The low energy
characteristics of F-theory GUTs consist of a deformation away from a minimal
gauge mediation scenario with a high messenger scale. The soft scalar masses of
the theory are all shifted by a stringy effect which survives to low energies.
This effect can range from 0 GeV up to ~ 500 GeV. In this paper we study
potential collider signatures of F-theory GUTs, focussing in particular on ways
to distinguish this class of models from other theories with an MSSM spectrum.
To accomplish this, we have adapted the general footprint method developed
recently for distinguishing broad classes of string vacua to the specific case
of F-theory GUTs. We show that with only 5 fb^(-1) of simulated LHC data, it is
possible to distinguish many mSUGRA models and low messenger scale gauge
mediation models from F-theory GUTs. Moreover, we find that at 5 fb^(-1), the
stringy deformation away from minimal gauge mediation produces observable
consequences which can also be detected to a level of order ~ +/- 80 GeV. In
this way, it is possible to distinguish between models with a large and small
stringy deformation. At 50 fb^(-1), this improves to ~ +/- 10 GeV.Comment: 85 pages, 37 figure
The Discovery of an Active Galactic Nucleus in the Late-type Galaxy NGC 3621: Spitzer Spectroscopic Observations
We report the discovery of an Active Galactic Nucleus (AGN) in the nearby SAd
galaxy NGC 3621 using Spitzer high spectral resolution observations. These
observations reveal the presence of [NeV] 14 um and 24 um emission which is
centrally concentrated and peaks at the position of the near-infrared nucleus.
Using the [NeV] line luminosity, we estimate that the nuclear bolometric
luminosity of the AGN is ~ 5 X 10^41 ergs s^-1, which corresponds based on the
Eddington limit to a lower mass limit of the black hole of ~ 4 X 10^3 Msun.
Using an order of magnitude estimate for the bulge mass based on the Hubble
type of the galaxy, we find that this lower mass limit does not put a strain on
the well-known relationship between the black hole mass and the host galaxy's
stellar velocity dispersion established in predominantly early-type galaxies.
Mutli-wavelength follow-up observations of NGC 3621 are required to obtain more
precise estimates of the bulge mass, black hole mass, accretion rate, and
nuclear bolometric luminosity. The discovery reported here adds to the growing
evidence that a black hole can form and grow in a galaxy with no or minimal
bulge.Comment: 5 pages, 7 figures, Accepted for publication in ApJ Letter
The Spatial Clustering of Low Luminosity AGN
We present the first multi-parameter analysis of the narrow line AGN
clustering properties. Estimates of the two-point correlation function (CF)
based on SDSS DR2 data reveal that Seyferts are clearly less clustered than
normal galaxies, while the clustering amplitude (r_0) of LINERs is consistent
with that of the parent galaxy population. The similarities in the host
properties (color and concentration index) of Seyferts and LINERs suggest that
the difference in their r_0 is not driven by the morphology-density relation.
We find that the luminosity of [O I] emission shows the strongest influence on
AGN clustering, with low L([O I]) sources having the highest r_0. This trend is
much stronger than the previously detected dependence on L([O III]), which we
confirm. There is a strong correspondence between the clustering patterns of
objects of given spectral type and their physical properties. LINERs, which
exhibit high r_0, show the lowest luminosities and obscuration levels, and
relatively low gas densities (n_e), suggesting that these objects harbor black
holes that are relatively massive yet weakly active or inefficient in their
accretion, probably due to the insufficiency of their fuel supply. Seyferts,
which have low r_0, are luminous and show large n_e, suggesting that their
black holes are less massive but accrete quickly and efficiently enough to
clearly dominate the ionization. The low r_0 of the H II galaxies can be
understood as a consequence of both the morphology-density and star formation
rate-density relations, however, their spectral properties suggest that their
centers hide amidst large amounts of obscuring material black holes of
generally low mass whose activity remains relatively feeble. Our own Milky Way
may be a typical such case.[abridged]Comment: 27 pages, color figures, some are severely degraded in resolution,
emulateapj. See http://www.physics.drexel.edu/~constant/work/agnclustering.ps
for high resolution version. Accepted to Ap
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