1,007 research outputs found
The Asia Minor Greek adpositional cycle: a tale of multiple causation
This paper examines the interplay of language-internal continuity and external influence in the cyclical development of the Asia Minor Greek adpositional system. The Modern Greek dialects of Asia Minor inherited an adpositional system of the Late Medieval Greek type whereby secondary adpositions regularly combined with primary adpositions to encode spatial region. Secondary adpositions could originally precede simple adpositions ([PREPOSITION + PREPOSITION + NPACC]) or follow the adpositional complement ([PREPOSITION + NPACC + POSTPOSITION]). Asia Minor Greek replicated the structure of Ottoman Turkish postpositional phrases to resolve this variability, fixing the position of secondary adpositions after the complement and thus developing circumpositions of the type [PREPOSITION + NPACC + POSTPOSITION]. Later, some varieties dropped the primary preposition SE from circumpositional phrases, leaving (secondary) postpositions as the only overt relator ([NPACC + POSTPOSITION]) in some environments. In addition, a number of Turkish postpositions were borrowed wholesale, thus enriching the Greek adpositional inventory
On the role of longitudinal momenta in high energy hadron-hadron scattering
We demonstrate a new method for the calculation of inelastic scattering
cross-section, which in contrary to the Regge-based methods takes into account
the energy momentum conservation law. By virtue of this method it was shown
that the main contribution to integral expressing inelastic scattering
cross-sections comes not from the multi-Regge domain. In particular this leads
to the fact that accounting of longitudinal momenta contribution to
virtualities is sufficient and results in the new mechanism of cross-section
growth. The necessity of taking into account the large number of interference
contributions is shown and the approximate method for this purpose is
developed. By considering the interference contributions from a single fitting
constant achieved a qualitative agreement of the total and inelastic cross
sections with experimental data.Comment: 38 pages, 19 figures (A misspelled author's name corrected
A Study in Depth of f0(1370)
Claims have been made that f0(1370) does not exist. The five primary sets of
data requiring its existence are refitted. Major dispersive effects due to the
opening of the 4pi threshold are included for the first time; the sigma -> 4pi
amplitude plays a strong role. Crystal Barrel data on pbar-p -> 3pizero at rest
require f0(1370) signals of at least 32 and 33 standard deviations in 1S0 and
3P1 annihilation respectively. Furthermore, they agree within 5 MeV for mass
and width. Data on pbar-p -> eta-eta-pizero agree and require at least a 19
standard deviation contribution. This alone is sufficient to demonstrate the
existence of f0(1370). BES II data for J/Psi -> phi-pi-pi contain a visible
f0(1370) signal > 8 standard devations. In all cases, a resonant phase
variation is required. The possibility of a second pole in the sigma amplitude
due to the opening of the 4pi channel is excluded. Cern-Munich data for pi-pi
elastic scattering are fitted well with the inclusion of some mixing between
sigma, f0(1370) and f0(1500). The pi-pi widths for f2(1565), rho3(1690),
rho3(1990) and f4(2040) are determined.Comment: 25 pages, 22 figures. Typos corrected in Eqs 2 and 7. Introduction
rewritten. Conclusions unchange
Universal features of the order-parameter fluctuations : reversible and irreversible aggregation
We discuss the universal scaling laws of order parameter fluctuations in any
system in which the second-order critical behaviour can be identified. These
scaling laws can be derived rigorously for equilibrium systems when combined
with the finite-size scaling analysis. The relation between order parameter,
criticality and scaling law of fluctuations has been established and the
connexion between the scaling function and the critical exponents has been
found. We give examples in out-of-equilibrium aggregation models such as the
Smoluchowski kinetic equations, or of at-equilibrium Ising and percolation
models.Comment: 19 pages, 10 figure
Jack superpolynomials with negative fractional parameter: clustering properties and super-Virasoro ideals
The Jack polynomials P_\lambda^{(\alpha)} at \alpha=-(k+1)/(r-1) indexed by
certain (k,r,N)-admissible partitions are known to span an ideal I^{(k,r)}_N of
the space of symmetric functions in N variables. The ideal I^{(k,r)}_N is
invariant under the action of certain differential operators which include half
the Virasoro algebra. Moreover, the Jack polynomials in I^{(k,r)}_N admit
clusters of size at most k: they vanish when k+1 of their variables are
identified, and they do not vanish when only k of them are identified. We
generalize most of these properties to superspace using orthogonal
eigenfunctions of the supersymmetric extension of the trigonometric
Calogero-Moser-Sutherland model known as Jack superpolynomials. In particular,
we show that the Jack superpolynomials P_{\Lambda}^{(\alpha)} at
\alpha=-(k+1)/(r-1) indexed by certain (k,r,N)-admissible superpartitions span
an ideal {\mathcal I}^{(k,r)}_N of the space of symmetric polynomials in N
commuting variables and N anticommuting variables. We prove that the ideal
{\mathcal I}^{(k,r)}_N is stable with respect to the action of the
negative-half of the super-Virasoro algebra. In addition, we show that the Jack
superpolynomials in {\mathcal I}^{(k,r)}_N vanish when k+1 of their commuting
variables are equal, and conjecture that they do not vanish when only k of them
are identified. This allows us to conclude that the standard Jack polynomials
with prescribed symmetry should satisfy similar clustering properties. Finally,
we conjecture that the elements of {\mathcal I}^{(k,2)}_N provide a basis for
the subspace of symmetric superpolynomials in N variables that vanish when k+1
commuting variables are set equal to each other.Comment: 36 pages; the main changes in v2 are : 1) in the introduction, we
present exceptions to an often made statement concerning the clustering
property of the ordinary Jack polynomials for (k,r,N)-admissible partitions
(see Footnote 2); 2) Conjecture 14 is substantiated with the extensive
computational evidence presented in the new appendix C; 3) the various tests
supporting Conjecture 16 are reporte
Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments
Magnesite forms a series of 1- to 15-m-thick beds within the approximate to2.0 Ga (Palaeoproterozoic) Tulomozerskaya Formation, NW Fennoscandian Shield, Russia. Drillcore material together with natural exposures reveal that the 680-m-thick formation is composed of a stromatolite-dolomite-'red bed' sequence formed in a complex combination of shallow-marine and non-marine, evaporitic environments. Dolomite-collapse breccia, stromatolitic and micritic dolostones and sparry allochemical dolostones are the principal rocks hosting the magnesite beds. All dolomite lithologies are marked by delta C-13 values from +7.1 parts per thousand to +11.6 parts per thousand (V-PDB) and delta O-18 ranging from 17.4 parts per thousand to 26.3 parts per thousand (V-SMOW). Magnesite occurs in different forms: finely laminated micritic; stromatolitic magnesite; and structureless micritic, crystalline and coarsely crystalline magnesite. All varieties exhibit anomalously high delta C-13 values ranging from +9.0 parts per thousand to +11.6 parts per thousand and delta O-18 values of 20.0-25.7 parts per thousand. Laminated and structureless micritic magnesite forms as a secondary phase replacing dolomite during early diagenesis, and replaced dolomite before the major phase of burial. Crystalline and coarsely crystalline magnesite replacing micritic magnesite formed late in the diagenetic/metamorphic history. Magnesite apparently precipitated from sea water-derived brine, diluted by meteoric fluids. Magnesitization was accomplished under evaporitic conditions (sabkha to playa lake environment) proposed to be similar to the Coorong or Lake Walyungup coastal playa magnesite. Magnesite and host dolostones formed in evaporative and partly restricted environments; consequently, extremely high delta C-13 values reflect a combined contribution from both global and local carbon reservoirs. A C- 13-rich global carbon reservoir (delta C-13 at around +5 parts per thousand) is related to the perturbation of the carbon cycle at 2.0 Ga, whereas the local enhancement in C-13 (up to +12 parts per thousand) is associated with evaporative and restricted environments with high bioproductivity
The influence of gene expression time delays on Gierer-Meinhardt pattern formation systems
There are numerous examples of morphogen gradients controlling long range signalling in developmental and cellular systems. The prospect of two such interacting morphogens instigating long range self-organisation in biological systems via a Turing bifurcation has been explored, postulated, or implicated in the context of numerous developmental processes. However, modelling investigations of cellular systems typically neglect the influence of gene expression on such dynamics, even though transcription and translation are observed to be important in morphogenetic systems. In particular, the influence of gene expression on a large class of Turing bifurcation models, namely those with pure kinetics such as the Gierer–Meinhardt system, is unexplored. Our investigations demonstrate that the behaviour of the Gierer–Meinhardt model profoundly changes on the inclusion of gene expression dynamics and is sensitive to the sub-cellular details of gene expression. Features such as concentration blow up, morphogen oscillations and radical sensitivities to the duration of gene expression are observed and, at best, severely restrict the possible parameter spaces for feasible biological behaviour. These results also indicate that the behaviour of Turing pattern formation systems on the inclusion of gene expression time delays may provide a means of distinguishing between possible forms of interaction kinetics. Finally, this study also emphasises that sub-cellular and gene expression dynamics should not be simply neglected in models of long range biological pattern formation via morphogens
- …