15,922 research outputs found
Monochromatic Clique Decompositions of Graphs
Let be a graph whose edges are coloured with colours, and be a -tuple of graphs. A monochromatic -decomposition of is a partition of the edge set of such that each
part is either a single edge or forms a monochromatic copy of in colour
, for some . Let be the smallest
number , such that, for every order- graph and every
-edge-colouring, there is a monochromatic -decomposition with at
most elements. Extending the previous results of Liu and Sousa
["Monochromatic -decompositions of graphs", Journal of Graph Theory},
76:89--100, 2014], we solve this problem when each graph in is a
clique and is sufficiently large.Comment: 14 pages; to appear in J Graph Theor
Effective restoration of the U_A(1) symmetry with temperature and density
We investigate the full U(3)U(3) chiral symmetry restoration, at
finite temperature and density, on the basis of a quark model which
incorporates the most relevant properties of QCD in this context: explicit and
spontaneous breaking of chiral symmetry and axial U(1) symmetry breaking. A
specific lattice-inspired behavior of the topological susceptibility, combined
with the convergence of chiral partners, signals the onset of an effective
chiral symmetry restoration. The results suggest that the axial part of the
symmetry is restored before the possible restoration of the full
U(3)U(3) chiral symmetry can occur. This conclusion is valid in the
context of both finite temperature and density.Comment: 5 pages, 2 figures; PRD versio
Euclidean thermal spinor Green's function in the spacetime of a straight cosmic string
Within the framework of the quantum field theory at finite temperature on a
conical space, we determine the Euclidean thermal spinor Green's function for a
massless spinor field. We then calculate the thermal average of the
energy-momentum tensor of a thermal bath of massless fermions. In the
high-temperature limit, we find that the straight cosmic string does not
perturb the thermal bathComment: 11 pages, latex, no figure
The new clash of generation
Unlike in the sixties, today's clash of generations is not about creating (post-)materialistic values. It is about human species survival. The fear of decay (of the Empire through war) and the hope of revolution ( coming back a new to a starting configuration) are similar. Social State´s financial sustainability or the new generation of energy sources are partial problems. How to have justice for all, including the environment?, that´s a global problem. The main and also repressed question is about how climate change will impose new ways of living on us all.Political and cognitive alienation from the main human problems is pushing emotional responses in different directions. Alienation closes political systems from population and from it springs populist irrationality in politics, racist and sexist scapegoating, consumers street uprisings, etc. Considering the regulatory function of the law over technology, social exclusion, war, one can assess the way modern law focuses on intergeneration relationships and how a healthy environment has been dismissed as a human right. For this propose one will consider the ongoing legal attempts to criminalize ecocide.info:eu-repo/semantics/publishedVersio
New strategies for pine wilt disease (PWD) management in Portugal: preventive methods to reduce the spread of the disease to new areas
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