7,065 research outputs found
The impact of ancestral population size and incomplete lineage sorting on Bayesian estimation of species divergence times
MdR was supported by Biotechnology and Biological Sciences Research Council (UK) grant BB/J009709/1 awarded to ZY
Weak nuclear forces cause the strong nuclear force
We determine the strength of the weak nuclear force which holds the lattices
of the elementary particles together. We also determine the strength of the
strong nuclear force which emanates from the sides of the nuclear lattices. The
strong force is the sum of the unsaturated weak forces at the surface of the
nuclear lattices. The strong force is then about ten to the power of 6 times
stronger than the weak force between two lattice points.Comment: 12 pages, 1 figur
Quantum Information and Wave function Collapse
Inofrmation-theoretical restrictions on information transferred in the
measurement of object S by information system O are studied. It is shown that
such constraints, induced by Heisenberg commutation relations, result in the
loss of information about the purity of S state. Consequently, it becomes
impossible for O to discriminate pure and mixed S states. In individual events
this effect is manifested by the stochastic outcomes of pure S state
measurement, i.e. the collapse of pure S state.Comment: 8 pages, talk given on Simposium 'Frontiers of fundamental Physics',
Udine, Italy, January 2008, to appear in Proceeding
The Speed of Light and the Hubble Parameter: The Mass-Boom Effect
We prove here that Newtons universal gravitation and momentum conservation
laws together reproduce Weinbergs relation. It is shown that the Hubble
parameter H must be built in this relation, or equivalently the age of the
Universe t. Using a wave-to-particle interaction technique we then prove that
the speed of light c decreases with cosmological time, and that c is
proportional to the Hubble parameter H. We see the expansion of the Universe as
a local effect due to the LAB value of the speed of light co taken as constant.
We present a generalized red shift law and find a predicted acceleration for
photons that agrees well with the result from Pioneer 10/11 anomalous
acceleration. We finally present a cosmological model coherent with the above
results that we call the Mass-Boom. It has a linear increase of mass m with
time as a result of the speed of light c linear decrease with time, and the
conservation of momentum mc. We obtain the baryonic mass parameter equal to the
curvature parameter, omega m = omega k, so that the model is of the type of the
Einstein static, closed, finite, spherical, unlimited, with zero cosmological
constant. This model is the cosmological view as seen by photons, neutrinos,
tachyons etc. in contrast with the local view, the LAB reference. Neither dark
matter nor dark energy is required by this model. With an initial constant
speed of light during a short time we get inflation (an exponential expansion).
This converts, during the inflation time, the Plancks fluctuation length of
10-33 cm to the present size of the Universe (about 1028 cm, constant from then
on). Thereafter the Mass-Boom takes care to bring the initial values of the
Universe (about 1015 gr) to the value at the present time of about 1055 gr.Comment: 15 pages, presented at the 9th Symposium on "Frontiers of Fundamental
Physics", 7-9 Jan. 2008, University of Udine, Italy. Changed content
Hidden-variable theory versus Copenhagen quantum mechanics
The main assumptions the Copenhagen quantum mechanics has been based on will
be summarized and the known (not yet decided) contradiction between Einstein
and Bohr will be newly analyzed. The given assumptions have been represented
basically by time-dependent Schroedinger equation, to which some further
assumptions have been added. Some critical comments have been raised against
the given mathematical model structure by Pauli (1933) and by Susskind and
Glogover (1964). They may be removed if only the Schroedinger equation is
conserved and the additional assumptions are abandoned, as shown recently. It
seems to be in contradiction to the numerous declarations that the Copenhagen
model has been approved by experimental results.
However, in the most of these experiments only the agreement with the mere
Schroedinger equation has been tested. All mentioned assumptions have been
tested practically only in the EPR experiment (measurement of coincidence light
transmission through two polarizers) proposed originally by Einstein (1935).
Also these experimental results have been interpreted as supporting the
Copenhagen alternative, which has not been, however, true. In fact the
microscopic world may be described correspondingly only with the help of the
hidden-variable theory that is represented by the Schroedinger equation without
mentioned additional assumptions, which has the consequence that the earlier
interpretation gap between microscopic and macroscopic worlds has been removed.
The only difference concerns the existence of discrete states. The
possibilities of the human reason of getting to know the nature will be also
shortly discussed in the beginning of this contribution.Comment: 10 pages, 2 figures; v2: local refinements and improvements of the
tex
Exact Ground State and Finite Size Scaling in a Supersymmetric Lattice Model
We study a model of strongly correlated fermions in one dimension with
extended N=2 supersymmetry. The model is related to the spin XXZ
Heisenberg chain at anisotropy with a real magnetic field on the
boundary. We exploit the combinatorial properties of the ground state to
determine its exact wave function on finite lattices with up to 30 sites. We
compute several correlation functions of the fermionic and spin fields. We
discuss the continuum limit by constructing lattice observables with well
defined finite size scaling behavior. For the fermionic model with periodic
boundary conditions we give the emptiness formation probability in closed form.Comment: 4 pages, 4 eps figure
Biological Principles in Self-Organization of Young Brain - Viewed from Kohonen Model
Variants of the Kohonen model are proposed to study biological principles of
self-organization in a model of young brain. We suggest a function to measure
aquired knowledge and use it to auto-adapt the topology of neuronal
connectivity, yielding substantial organizational improvement relative to the
standard model. In the early phase of organization with most intense learning,
we observe that neural connectivity is of Small World type, which is very
efficient to organize neurons in response to stimuli. In analogy to human brain
where pruning of neural connectivity (and neuron cell death) occurs in early
life, this feature is present also in our model, which is found to stabilize
neuronal response to stimuli
Drag Reduction by Polymers in Turbulent Channel Flows: Energy Redistribution Between Invariant Empirical Modes
We address the phenomenon of drag reduction by dilute polymeric additive to
turbulent flows, using Direct Numerical Simulations (DNS) of the FENE-P model
of viscoelastic flows. It had been amply demonstrated that these model
equations reproduce the phenomenon, but the results of DNS were not analyzed so
far with the goal of interpreting the phenomenon. In order to construct a
useful framework for the understanding of drag reduction we initiate in this
paper an investigation of the most important modes that are sustained in the
viscoelastic and Newtonian turbulent flows respectively. The modes are obtained
empirically using the Karhunen-Loeve decomposition, allowing us to compare the
most energetic modes in the viscoelastic and Newtonian flows. The main finding
of the present study is that the spatial profile of the most energetic modes is
hardly changed between the two flows. What changes is the energy associated
with these modes, and their relative ordering in the decreasing order from the
most energetic to the least. Modes that are highly excited in one flow can be
strongly suppressed in the other, and vice versa. This dramatic energy
redistribution is an important clue to the mechanism of drag reduction as is
proposed in this paper. In particular there is an enhancement of the energy
containing modes in the viscoelastic flow compared to the Newtonian one; drag
reduction is seen in the energy containing modes rather than the dissipative
modes as proposed in some previous theories.Comment: 11 pages, 13 figures, included, PRE, submitted, REVTeX
CHC-COMP 2022: Competition Report
CHC-COMP 2022 is the fifth edition of the competition of solvers for
Constrained Horn Clauses. The competition was run in March 2022; the results
were presented at the 9th Workshop on Horn Clauses for Verification and
Synthesis held in Munich, Germany, on April 3, 2022. This edition featured six
solvers, and eight tracks consisting of sets of linear and nonlinear clauses
with constraints over linear integer arithmetic, linear real arithmetic,
arrays, and algebraic data types. This report provides an overview of the
organization behind the competition runs: it includes the technical details of
the competition setup as well as presenting the results of the 2022 edition.Comment: In Proceedings HCVS/VPT 2022, arXiv:2211.10675. arXiv admin note:
text overlap with arXiv:2109.04635, arXiv:2008.02939 by other author
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