2,048 research outputs found
On the twisted chiral potential in 2d and the analogue of rigid special geometry for 4-folds
We discuss how to obtain an N=(2,2) supersymmetric SU(3) gauge theory in two
dimensions via geometric engineering from a Calabi-Yau 4-fold and compute its
non-perturbative twisted chiral potential. The relevant compact part of the
4-fold geometry consists of two intersecting P^1's fibered over P^2. The rigid
limit of the local mirror of this geometry is a complex surface that
generalizes the Seiberg-Witten curve and on which there exist two holomorphic
2-forms. These stem from the same meromorphic 2-form as derivatives w.r.t. the
two moduli, respectively. The middle periods of this meromorphic form give
directly the twisted chiral potential. The explicit computation of these and of
the four-point Yukawa couplings allows for a non-trivial test of the analogue
of rigid special geometry for a 4-fold with several moduli.Comment: 20 pages, LaTeX, no figures; v2: discussion of FI-couplings in
section 3 and appendix enlarged, version to appear in JHE
Perceptions of Peace and Reconciliation: Case of Lokokwo Peyot Women’s Group in Paidwe Parish, Bobi Sub-County
This research project explores perceptions of peace and reconciliation among female members of the Lokokwo Peyot Women’s Group in Paidwe Parish, Bobi Sub-County, Gulu District. It aims to understand how women define the concepts of peace and reconciliation and how women currently perceive peace and reconciliation within their community. It also attempts to further understand these perceptions through examining the women’s past experiences and current challenges. The project displays the impact of women’s involvement in peacebuilding and conflict mediation in a region that is desperately trying to recover from decades of destruction and violence.
Research was carried out at two separate but related locations in Gulu District: the home of the Lokokwo Peyot group’s Chairperson in Paidwe Parish within Bobi Sub-County, and the main office of Gulu Women’s Economic Development and Globalization (GWED-G) in Gulu Municipality. Eleven individual interviews and two group discussions form the foundation of this project. The focus on the Lokokwo Peyot Women’s Group was made possible through the assistance and cooperation of GWED-G staff members, and the interested group members who so generously donated their time and experiences.
This study discovered that women in the Lokokwo Peyot group have witnessed significant changes personally and locally since the group’s founding in 2009, and they feel that an environment of relative peace has developed in the community. Although traditionally women do not speak publicly or actively participate in community meetings, the women’s involvement in the group challenges such cultural norms and allows them to feel empowered and respected. By promoting a peaceful environment from within their individual homes and villages, group members have succeeded in decreasing the level of conflict and violence present
Investigating Sexual Violence as a Weapon of War in the Democratic Republic of Congo (DRC) Through Critical Discourse Analysis
This paper addresses the large-scale sexual violence that has taken place (and still continues) within the Democratic Republic of Congo (DRC) using critical discourse analysis. Disturbing statistics have resulted in the identification of the DRC as the rape capital of the world, and a variety of national, regional, and international actors have employed sexual violence as a weapon of war. Victims frequently receive little assistance, perpetrators act without fear of serious repercussions, and the government of the DRC fails to successfully implement relative legislation. Through an investigation of the discourse surrounding victims, perpetrators, and political institutions respectively, I will develop an understanding of how specific language portrays each of these participants in multiple reports and publications, and how this discourse can shape one\u27s perspective of the complex situation the DRC faces involving sexual violence
Thermal analysis and design of a cooling system for a Mach 14 nozzle
The analysis and design of a Mach 14 converging diverging nozzle wall liner is provided. The analysis indicates that: no fin on the coolant side of the nozzle wall is optimum, the thermal stresses are dominant, and the critical area is very near the throat. The molybdenum alloy TZM, with a wall thickness of 2.0 mm in the throat area, appears to be the only material capable of meeting design requirements. Additionally, cooling water at 2000 psia with a flow velocity of 25 m/s in the coolant passages is required
Phases of supersymmetric gauge theories from M-theory on G_2 manifolds
We consider M-theory on compact spaces of G_2 holonomy constructed as
orbifolds of the form (CY x S^1)/Z_2 with fixed point set \Sigma on the CY.
This describes N=1 SU(2) gauge theories with b_1(\Sigma) chiral multiplets in
the adjoint. For b_1=0, it generalizes to compact manifolds the study of the
phase transition from the non-Abelian to the confining phase through
geometrical S^3 flops. For b_1=1, the non-Abelian and Coulomb phases are
realized, where the latter arises by desingularization of the fixed point set,
while an S^2 x S^1 flop occurs. In addition, an extremal transition between G_2
spaces can take place at conifold points of the CY moduli space where
unoriented membranes wrapped on CP^1 and RP^2 become massless.Comment: 21 pages, LaTeX, v2: mistake in spectra corrected, reference added,
v3: one more reference added, version published in JHE
An N=1 Triality by Spectrum Matching
On promoting the type IIA side of the N=1 Heterotic/type IIA dual pairs of
[1] to M-theory on a `barely G_2 Manifold' of [2], by spectrum-matching we show
a possible triality between Heterotic on a self-mirror Calabi-Yau, M-theory on
the above `barely G_2-Manifold' constructed from the Calabi-Yau on the type IIA
side and -theory on an elliptically fibered Calabi-Yau 4-fold fibered over a
trivially rationally ruled CP^1 x E base, E being the Enriques surface. We
raise an apparent puzzle on the F-theory side, namely, the Hodge data of the
4-fold derived can not be obtained by a naive freely acting orbifold of
CY_3(3,243) x T^2 as one might have guessed on the basis of arguments related
to dualities involving string, M and (definition of) F theories. There are some
interesting properties of the antiholomorphic involution used in \cite{VW} for
constructing the type IIA orientifold and by us in constructing the 'barely G_2
manifold', that we also study.Comment: 14 pages, LaTex; v3: journal versio
Livatn og Høyeåna. Vannkvalitetsutvikling 1982-1993
Konsentrasjonen av totalfosfor i Livatn var i 1992-93 omlag på nivå med resultatene fra 1982. Pga. noe høyere humusinnhold i 1992-93, kan en forvente en høyere naturlig bakgrunnsverdi for fosfor. Dette kan indikere en viss reduksjon av de menneskeskapte tilførslene siden 1982. Konsentrasjonen av totalnitrogen var noe laver i 1992-93, sammenlignet med 1982 og 1985. Nitrogentilførelene vil variere naturlig fra år til år avhengig av klimaforhold, men noe av nedgangen kan skyldes avløpstiltak i området. Algemengdene var i 1992 lavere enn i 1982, men høyere enn i 1985. Store svinginger gjør det vanskelig å avgjøre om det er oppnådd en generell reduksjon av algekonsentrasjonen i løpet av de siste ti årene. Innholdet av termostabile koliforme bakterier var i 1992-93 lavere enn tilsvarende målinger 1985. Vassdraget er forsuret, men det er store pH-variasjoner gjennom året. Hele vassdraget inneholder forholdsvis mye aluminium pga. forsuringen. pH-verdien i vassdraget var noe høyere enn i 1982 og 1985. Høyeåna utgjør omlag 5% av vannføringen i Mandaslselva nedstrøms samløpet mellom de to elvene. Det må derfor være ekstreme avvik i vannføring og surhet for at Høyeåna kan påvirke vannkvaliteten i Mandalselva i nevneverdig grad. Høyeåna har gjennomgående høyere pH-verdier enn Mandalselva
Nontrivial RR two-form field strength and SU(3)-structure
We discuss how in the presence of a nontrivial RR two-form field strength and
nontrivial dilaton the conditions of preserving supersymmetry on
six-dimensional manifolds lead to generalized monopole and Killing spinor
equations. We show that the manifold is K\"ahler in the ten-dimensional string
frame if F_0^{(1,1)}=0. We then determine explicitly the intrinsic torsion of
the SU(3)-structure on six-manifolds that result via Kaluza-Klein reduction
from seven-manifolds with G_2-structure of generic intrinsic torsion. Lastly we
give explicitly the intrinsic torsion of the SU(3)-structure for an N=1
supersymmetric background in the presence of nontrivial RR two-form field
strength and nontrivial dilaton.Comment: LaTeX, 8 pages, talk given at the 35th Symposium Ahrenshoop, enlarged
version of the contribution to the proceeding
Mirror symmetric SU(3)-structure manifolds with NS fluxes
When string theory is compactified on a six-dimensional manifold with a
nontrivial NS flux turned on, mirror symmetry exchanges the flux with a purely
geometrical composite NS form associated with lack of integrability of the
complex structure on the mirror side. Considering a general class of
T^3-fibered geometries admitting SU(3) structure, we find an exchange of pure
spinors (e^{iJ} and \Omega) in dual geometries under fiberwise T-duality, and
study the transformations of the NS flux and the components of intrinsic
torsion. A complementary study of action of twisted covariant derivatives on
invariant spinors allows to extend our results to generic geometries and
formulate a proposal for mirror symmetry in compactifications with NS flux.Comment: 21 pages, LaTe
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