319 research outputs found
Integrability on the Master Space
It has been recently shown that every SCFT living on D3 branes at a toric
Calabi-Yau singularity surprisingly also describes a complete integrable
system. In this paper we use the Master Space as a bridge between the
integrable system and the underlying field theory and we reinterpret the
Poisson manifold of the integrable system in term of the geometry of the field
theory moduli space.Comment: 47 pages, 20 figures, using jheppub.st
Emerging Non-Anomalous Baryonic Symmetries in the AdS_5/CFT_4 Correspondence
We study the breaking of baryonic symmetries in the AdS_5/CFT_4
correspondence for D3 branes at Calabi-Yau three-fold singularities. This
leads, for particular VEVs, to the emergence of non-anomalous baryonic
symmetries during the renormalization group flow. We claim that these VEVs
correspond to critical values of the B-field moduli in the dual supergravity
backgrounds. We study in detail the C^3/Z_3 orbifold, the cone over F_0 and the
C^3/Z_5 orbifold. For the first two examples, we study the dual supergravity
backgrounds that correspond to the breaking of the emerging baryonic symmetries
and identify the expected Goldstone bosons and global strings in the infra-red.
In doing so we confirm the claim that the emerging symmetries are indeed
non-anomalous baryonic symmetries.Comment: 65 pages, 15 figures;v2: minor changes, published versio
Scattering Amplitudes and Toric Geometry
In this paper we provide a first attempt towards a toric geometric
interpretation of scattering amplitudes. In recent investigations it has indeed
been proposed that the all-loop integrand of planar N=4 SYM can be represented
in terms of well defined finite objects called on-shell diagrams drawn on
disks. Furthermore it has been shown that the physical information of on-shell
diagrams is encoded in the geometry of auxiliary algebraic varieties called the
totally non negative Grassmannians. In this new formulation the infinite
dimensional symmetry of the theory is manifest and many results, that are quite
tricky to obtain in terms of the standard Lagrangian formulation of the theory,
are instead manifest. In this paper, elaborating on previous results, we
provide another picture of the scattering amplitudes in terms of toric
geometry. In particular we describe in detail the toric varieties associated to
an on-shell diagram, how the singularities of the amplitudes are encoded in
some subspaces of the toric variety, and how this picture maps onto the
Grassmannian description. Eventually we discuss the action of cluster
transformations on the toric varieties. The hope is to provide an alternative
description of the scattering amplitudes that could contribute in the
developing of this very interesting field of research.Comment: 58 pages, 25 figures, typos corrected, a reference added, to be
published in JHE
Counting Chiral Operators in Quiver Gauge Theories
We discuss in detail the problem of counting BPS gauge invariant operators in
the chiral ring of quiver gauge theories living on D-branes probing generic
toric CY singularities. The computation of generating functions that include
counting of baryonic operators is based on a relation between the baryonic
charges in field theory and the Kaehler moduli of the CY singularities. A study
of the interplay between gauge theory and geometry shows that given geometrical
sectors appear more than once in the field theory, leading to a notion of
"multiplicities". We explain in detail how to decompose the generating function
for one D-brane into different sectors and how to compute their relevant
multiplicities by introducing geometric and anomalous baryonic charges. The
Plethystic Exponential remains a major tool for passing from one D-brane to
arbitrary number of D-branes. Explicit formulae are given for few examples,
including C^3/Z_3, F_0, and dP_1.Comment: 75 pages, 22 figure
M2-Branes and Fano 3-folds
A class of supersymmetric gauge theories arising from M2-branes probing
Calabi-Yau 4-folds which are cones over smooth toric Fano 3-folds is
investigated. For each model, the toric data of the mesonic moduli space is
derived using the forward algorithm. The generators of the mesonic moduli space
are determined using Hilbert series. The spectrum of scaling dimensions for
chiral operators is computed.Comment: 128 pages, 39 figures, 42 table
N=2 solutions of massive type IIA and their Chern-Simons duals
We find explicit AdS4 solutions of massive type IIA with N=2 supersymmetry
obtained deforming with a Roman mass the type IIA supersymmetric reduction of
the M theory background AdS4 times M111. The family of solutions have SU(3)
times SU(3) structure and isometry SU(3) times U(1)^2. They are conjectured to
be dual to three-dimensional N=2 Chern-Simons theories with generic
Chern-Simons couplings and gauge group ranks.Comment: 20 pages, 1 figure, comments and references adde
Counting Exceptional Instantons
We show how to obtain the instanton partition function of N=2 SYM with
exceptional gauge group EFG using blow-up recursion relations derived by
Nakajima and Yoshioka. We compute the two instanton contribution and match it
with the recent proposal for the superconformal index of rank 2 SCFTs with E6,
E7 global symmetry.Comment: 16 pages, references adde
Weed Seed Bank Emergence across the Corn Belt
Field experiments, conducted from 1991 to 1994, generated information on weed seedbank emergence for 22 site-years from Ohio to Colorado and Minnesota to Missouri. Early spring seedbank densities were estimated through direct extraction of viable seeds from soil cores. Emerged seedlings were recorded periodically, as were daily values for air and soil temperature, and precipitation. Percentages of weed seedbanks that emerged as seedlings were calculated from seedbank and seedling data for each species, and relationships between seedbank emergence and microclimatic variables were sought. Fifteen species were found in 3 or more site-years. Average emergence percentages (and coefficients of variation) of these species were as follows: giant foxtail, 31.2 (84%); velvetleaf, 28.2 (66); kochia, 25.7 (79); Pennsylvania smartweed, 25.1 (65); common purslane, 15.4 (135); common ragweed, 15.0 (110); green foxtail, 8.5 (72); wild proso millet, 6.6 (104); hairy nightshade, 5.2 (62); common sunflower, 5.0 (26); yellow foxtail, 3.4 (67); pigweed species, 3.3 (103); common lambsquarters, 2.7 (111); wild buckwheat, 2.5 (63), and prostrate knotweed, 0.6 (79). Variation among site-years, for some species, could be attributed to microclimate variables thought to induce secondary dormancy in spring. For example, total seasonal emergence percentage of giant foxtail was related positively to the 1st date at which average daily soil temperature at 5 to 10 cm soil depth reached 16 C. Thus, if soil warmed before mid April, secondary dormancy was induced and few seedlings emerged, whereas many seedlings emerged if soil remained cool until June
Baryonic Generating Functions
We show how it is possible to use the plethystic program in order to compute
baryonic generating functions that count BPS operators in the chiral ring of
quiver gauge theories living on the world volume of D branes probing a non
compact CY manifold. Special attention is given to the conifold theory and the
orbifold C^2/Z_2 times C, where exact expressions for generating functions are
given in detail. This paper solves a long standing problem for the
combinatorics of quiver gauge theories with baryonic moduli spaces. It opens
the way to a statistical analysis of quiver theories on baryonic branches.
Surprisingly, the baryonic charge turns out to be the quantized Kahler modulus
of the geometry.Comment: 44 pages, 7 figures; fonts change
Neutrino Masses, Baryon Asymmetry, Dark Matter and the Moduli Problem : A Complete Framework
Recent developments in string theory have led to "realistic" string
compactifications which lead to moduli stabilization while generating a
hierarchy between the Electroweak and Planck scales at the same time. However,
this seems to suggest a rethink of our standard notions of cosmological
evolution after the end of inflation and before the beginning of BBN. We argue
that within classes of realistic string compactifications, there generically
exists a light modulus with a mass comparable to that of the gravitino which
generates a large late-time entropy when it decays. Therefore, all known
mechanisms of generating the baryon asymmetry of the Universe in the literature
have to take this fact into account. In this work, we find that it is still
possible to naturally generate the observed baryon asymmetry of the Universe as
well as light left-handed neutrino masses from a period of Affleck-Dine(AD)
leptogenesis shortly after the end of inflation, in classes of realistic string
constructions with a minimal extension of the MSSM below the unification scale
(consisting only of right-handed neutrinos) and satisfying certain microscopic
criteria described in the text. The consequences are as follows. The lightest
left-handed neutrino is required to be virtually massless. The moduli
(gravitino) problem can be naturally solved in this framework both within
gravity and gauge mediation. The observed upper bound on the relic abundance
constrains the moduli-matter and moduli-gravitino couplings since the DM is
produced non-thermally within this framework. Finally, although not a definite
prediction, the framework naturally allows a light right-handed neutrino and
sneutrinos around the electroweak scale which could have important implications
for DM as well as the LHC.Comment: 41 pages, no figures, journal version adde
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