1,182 research outputs found
On Upward Drawings of Trees on a Given Grid
Computing a minimum-area planar straight-line drawing of a graph is known to
be NP-hard for planar graphs, even when restricted to outerplanar graphs.
However, the complexity question is open for trees. Only a few hardness results
are known for straight-line drawings of trees under various restrictions such
as edge length or slope constraints. On the other hand, there exist
polynomial-time algorithms for computing minimum-width (resp., minimum-height)
upward drawings of trees, where the height (resp., width) is unbounded.
In this paper we take a major step in understanding the complexity of the
area minimization problem for strictly-upward drawings of trees, which is one
of the most common styles for drawing rooted trees. We prove that given a
rooted tree and a grid, it is NP-hard to decide whether
admits a strictly-upward (unordered) drawing in the given grid.Comment: Appears in the Proceedings of the 25th International Symposium on
Graph Drawing and Network Visualization (GD 2017
Differential Subordinations Involving Generalized Bessel Functions
In this paper our aim is to present some subordination and superordination
results, by using an operator, which involves the normalized form of the
generalized Bessel functions of first kind. These results are obtained by
investigating some appropriate classes of admissible functions. We obtain also
some sandwich-type results and we point out various known or new special cases
of our main results.Comment: 15 pages, accepted in Bulletin of the Malaysian Mathematical Sciences
Societ
Phenomenology of Light Sneutrino Dark Matter in cMSSM/mSUGRA with Inverse Seesaw
We study the possibility of a light Dark Matter (DM) within a constrained
Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM
singlet-pair sector to account for the non-zero neutrino masses by inverse
seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed
at high scale and the singlet neutrino sector at low scale, we find that,
contrary to the case of the usual cMSSM where the neutralino DM cannot be very
light, we can have a light sneutrino DM with mass below 100 GeV satisfying all
the current experimental constraints from cosmology, collider as well as
low-energy experiments. We also note that the supersymmetric inverse seesaw
mechanism with sneutrino as the lightest supersymmetric partner can have
enhanced same-sign dilepton final states with large missing transverse energy
(mET) coming from the gluino- and squark-pair as well as the squark-gluino
associated productions and their cascade decay through charginos. We present a
collider study for the same-sign dilepton+jets+mET signal in this scenario and
propose some distinctions with the usual cMSSM. We also comment on the
implications of such a light DM scenario on the invisible decay width of an 125
GeV Higgs boson.Comment: 24 pages, 4 figures, 7 tables; matches published versio
Negotiating power relations, gender equality, and collective agency: are village health committees transformative social spaces in northern India?
BACKGROUND: Participatory health initiatives ideally support progressive social change and stronger collective agency
for marginalized groups. However, this empowering potential is often limited by inequalities within communities and
between communities and outside actors (i.e. government officials, policymakers). We examined how the participatory
initiative of Village Health, Sanitation, and Nutrition Committees (VHSNCs) can enable and hinder the renegotiation of
power in rural north India.
METHODS: Over 18 months, we conducted 74 interviews and 18 focus groups with VHSNC members (including female
community health workers and local government officials), non-VHSNC community members, NGO staff, and higherlevel
functionaries. We observed 54 VHSNC-related events (such as trainings and meetings). Initial thematic network
analysis supported further examination of power relations, gendered “social spaces,” and the “discourses of
responsibility” that affected collective agency.
RESULTS: VHSNCs supported some re-negotiation of intra-community inequalities, for example by enabling some
women to speak in front of men and perform assertive public roles. However, the extent to which these new gender
dynamics transformed relations beyond the VHSNC was limited. Furthermore, inequalities between the community
and outside stakeholders were re-entrenched through a “discourse of responsibility”: The comparatively powerful
outside stakeholders emphasized community responsibility for improving health without acknowledging or correcting
barriers to effective VHSNC action. In response, some community members blamed peers for not taking up this
responsibility, reinforcing a negative collective identity where participation was futile because no one would work for
the greater good. Others resisted this discourse, arguing that the VHSNC alone was not responsible for taking action:
Government must also intervene. This counter-narrative also positioned VHSNC participation as futile.
CONCLUSIONS: Interventions to strengthen participation in health systems can engender social transformation. However
they must consider how changing power relations can be sustained outside participatory spaces, and how discourse
frames the rationale for community participation.ISIScopu
Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV
We present limits on anomalous WWZ and WW-gamma couplings from a search for
WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p
-> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron
Collider during the 1992-1995 run. The data sample corresponds to an integrated
luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling
parameters, the 95% CL limits on the CP-conserving couplings are
-0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a
form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also
presented.Comment: 11 pages, 2 figures, 2 table
Search for New Physics in e mu X Data at D0 Using Sleuth: A Quasi-Model-Independent Search Strategy for New Physics
We present a quasi-model-independent search for the physics responsible for
electroweak symmetry breaking. We define final states to be studied, and
construct a rule that identifies a set of relevant variables for any particular
final state. A new algorithm ("Sleuth") searches for regions of excess in those
variables and quantifies the significance of any detected excess. After
demonstrating the sensitivity of the method, we apply it to the semi-inclusive
channel e mu X collected in 108 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV
at the D0 experiment during 1992-1996 at the Fermilab Tevatron. We find no
evidence of new high p_T physics in this sample.Comment: 23 pages, 12 figures. Submitted to Physical Review
Search For Heavy Pointlike Dirac Monopoles
We have searched for central production of a pair of photons with high
transverse energies in collisions at TeV using of data collected with the D\O detector at the Fermilab Tevatron in
1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could
rescatter pairs of nearly real photons into this final state via a box diagram.
We observe no excess of events above background, and set lower 95% C.L. limits
of on the mass of a spin 0, 1/2, or 1 Dirac
monopole.Comment: 12 pages, 4 figure
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