41,526 research outputs found
On Universal Cycles for new Classes of Combinatorial Structures
A universal cycle (u-cycle) is a compact listing of a collection of
combinatorial objects. In this paper, we use natural encodings of these objects
to show the existence of u-cycles for collections of subsets, matroids,
restricted multisets, chains of subsets, multichains, and lattice paths. For
subsets, we show that a u-cycle exists for the -subsets of an -set if we
let vary in a non zero length interval. We use this result to construct a
"covering" of length for all subsets of of size
exactly with a specific formula for the term. We also show that
u-cycles exist for all -length words over some alphabet which
contain all characters from Using this result we provide
u-cycles for encodings of Sperner families of size 2 and proper chains of
subsets
A Fat Higgs with a Fat Top
A new variant of the supersymmetric Fat Higgs model is presented in which the
MSSM Higgses as well as the top quark are composite. The underlying theory is
an s-confining SU(3) gauge theory with the MSSM gauge groups realized as gauged
sub-groups of the chiral flavor symmetries. This motivates the large Yukawas
necessary for the large top mass and SM-like Higgs of mass>>M_Z in a natural
way as the residual of the strong dynamics responsible for the composites. This
removes fine-tuning associated with these couplings present in the original Fat
Higgs and New Fat Higgs models, respectively.Comment: 17 pages, 4 figures, Latex2e, uses JHEP3.cls and youngtab.sty, new
references adde
A Theory of time-varying Constants
We present a flat (K=0) cosmological model, described by a perfect fluid with
the ``constants'' and varying with cosmological time . We
introduce Planck\'s ``constant'' in the field equations through the
equation of state for the energy density of radiation. We then determine the
behaviour of the ``constants'' by using the zero divergence of the second
member of the modified Einstein\'s field equations i.e.
together with the
equation of state and the Einstein cosmological equations. Assuming realistic
physical and mathematical conditions we obtain a consistent result with . In this way we obtain gauge invariance for the Schr\"{o}dinger
equation and the behaviour of the remaining ``constants''Comment: 15 pages, RevTeX
ASSESSING SUSTAINABILITY IN AGRICULTURE: A MULTICRITERIA APPROACH
Environmental Economics and Policy,
Appetitive and Aversive Goal Values Are Encoded in the Medial Orbitofrontal Cortex at the Time of Decision Making
An essential feature of choice is the assignment of goal values (GVs) to the different options under consideration at the time of decision making. This computation is done when choosing among appetitive and aversive items. Several groups have studied the location of GV computations for appetitive stimuli, but the problem of valuation in aversive contexts at the time of decision making has been ignored. Thus, although dissociations between appetitive and aversive components of value signals have been shown in other domains such as anticipatory and outcome values, it is not known whether appetitive and aversive GVs are computed in similar brain regions or in separate ones. We investigated this question using two different functional magnetic resonance imaging studies while human subjects placed real bids in an economic auction for the right to eat/avoid eating liked/disliked foods. We found that activity in a common area of the medial orbitofrontal cortex and the dorsolateral prefrontal cortex correlated with both appetitive and aversive GVs. These findings suggest that these regions might form part of a common network
Non-commutative p-adic L-functions for supersingular primes
Let E/Q be an elliptic curve with good supersingular reduction at p with
a_p(E)=0. We give a conjecture on the existence of analytic plus and minus
p-adic L-functions of E over the Zp-cyclotomic extension of a finite Galois
extension of Q where p is unramified. Under some technical conditions, we adopt
the method of Bouganis and Venjakob for p-ordinary CM elliptic curves to
construct such functions for a particular non-abelian extension.Comment: 13 pages; some minor corrections; to appear in International Journal
of Number Theor
Dogmatism and Theoretical Pluralism in Modern Cosmology
This work discusses the presence of a dogmatic tendency within modern
cosmology, and some ideas capable of neutralizing its negative influence. It is
verified that warnings about the dangers of dogmatic thinking in cosmology can
be found as early as the 1930's, and we discuss the modern appearance of
"scientific dogmatism". The solution proposed to counteract such an influence,
which is capable of neutralizing this dogmatic tendency, has its origins in the
philosophical thinking of the Austrian physicist Ludwig Boltzmann (1844-1906).
In particular we use his two main epistemological theses, scientific theories
as representations of nature and theoretical pluralism, to show that once they
are embodied in the research practice of modern cosmology, there is no longer
any reason for dogmatic behaviours.Comment: 14 pages; LaTeX sourc
- …