共查询到20条相似文献,搜索用时 812 毫秒
1.
Saulius Mickevičius Darius Germanas Ramutis K. Kalinauskas 《Central European Journal of Physics》2012,10(2):421-428
We present a new independent scheme of SO(3) group transformations suitable for the N particle system, composed of N − 1 and 1 particle subsystems, where N − 1 particles have their own intrinsic clusterization. The simple expressions for corresponding four-particle harmonic-oscillator
transformation brackets are presented, as well as their simplifications for the special values of mass ratio parameters d = 0, d → ∞ and d
1 = 0, d
1 → ∞. 相似文献
2.
H. J. Herrmann 《Zeitschrift für Physik B Condensed Matter》1981,43(1):55-60
Exact solution of the one-dimensional quantumq-state Potts model for finite chains and subsequent finite-size analysis yields values for the thermal critical exponenty=1/v forq=3 andq=4. By taking into account the shift of the critical point due to the finite size we obtainy=1.48±0.01 forq=4 in good agreement with they=3/2 conjectured by den Nijs. Using the conjecture of den Nijs we find evidence for a logarithmic factor forq=4 but not forq=3. 相似文献
3.
Remco van der Hofstad Frank den Hollander Gordon Slade 《Communications in Mathematical Physics》2002,231(3):435-461
We construct the incipient infinite cluster measure (IIC) for sufficiently spread-out oriented percolation on ℤ
d
× ℤ+, for d +1 > 4+1. We consider two different constructions. For the first construction, we define ℙ
n
(E) by taking the probability of the intersection of an event E with the event that the origin is connected to (x,n) ℤ
d
× ℤ+, summing this probability over x ℤ
d
, and normalising the sum to get a probability measure. We let n → ∞ and prove existence of a limiting measure ℙ∞, the IIC. For the second construction, we condition the connected cluster of the origin in critical oriented percolation
to survive to time n, and let n → ∞. Under the assumption that the critical survival probability is asymptotic to a multiple of n
−1, we prove existence of a limiting measure ℚ∞, with ℚ∞ = ℙ∞. In addition, we study the asymptotic behaviour of the size of the level set of the cluster of the origin, and the dimension
of the cluster of the origin, under ℙ∞. Our methods involve minor extensions of the lace expansion methods used in a previous paper to relate critical oriented
percolation to super-Brownian motion, for d+1 > 4+1.
Received: 13 December 2001 / Accepted: 11 July 2002 Published online: 29 October 2002
RID="*"
ID="*" Present address: Department of Mathematics and Computer Science, Eindhoven University of Technology, P.O. Box 513,
5600 MB Eindhoven, The Netherlands. E-mail: rhofstad@win.tue.nl 相似文献
4.
The net charges on various atoms of poly (l-alanine), polyglycine, poly (N-methyl-l-alanine) and poly (N-methylglycine) were computed using the MOLCAO method of Del Re forσ charges and the Hückel MO method forπ charges. The characteristic ratiosC
∞ were computed for all the above polypeptide chains, with different sets of parameters for the peptide unit. The calculated
values ofC
∞ are found to be very sensitive to the input peptide geometry. The calculated value of 2·2 forC
∞ of poly (N-methylglycine) obtained with set-3 parameters (derived from a crystal structure containing prolyl residue) is
closer to the experimental value of 1·8±0·2 than the value of 2·7 obtained with set 1 (Pauling-Corey parameters), suggesting
that the peptide parameters of N-substituted aminoacids have close similarity to set 3 rather than to set 1. The calculated
values ofC
∞ of the polypeptide chains show no correlation with the number of allowed conformations, suggesting that the ratio ofC
∞/C
f need not always provide information about the flexibility or freedom of rotation of chain units.
Contribution No. 57 from the Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, INDIA. 相似文献
5.
By using the second-order moment of the power density, the beam width, far-field divergence angle and M2 factor of nonparaxial truncated flattened Gaussian (FG) beams are derived analytically. It is shown that the M2 factor of nonparaxial truncated FG beams depends not only on the truncation parameter δ and beam order N, but also on the initial waist-width to wavelength ratio w0/λ. The far-field divergence angle approaches an asymptotic value of θmax=63.435° when the truncation parameter δ → 0. For the special cases of N = 0 and δ → ∞ our results reduce to those of nonparaxial truncated Gaussian beams and nonparaxial untruncated FG beams, respectively. 相似文献
6.
S. Havlin M. Araujo H. Larralde A. Shehter H. E. Stanley P. Trunfio 《Il Nuovo Cimento D》1994,16(8):1039-1051
Summary We review recent developments in the study of the diffusion reaction systems of the type A+B→C in which the reactants are
initially separated. We consider the case where the A and B particles are initially placed uniformly in Euclidean space atx>0 andx<0, respectively. We find that whereas ford≥2 the mean-field exponent characterizes the width of the reaction zone, fluctuations are relevant in the one-dimensional
system. We also presented analytical and numerical results for the reaction rate on fractals and percolation systems.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献
7.
K. A. Bronnikov B. E. Meierovich 《Journal of Experimental and Theoretical Physics》2008,106(2):247-264
We consider (d
0 + 2)-dimensional configurations with global strings in two extra dimensions and a flat metric in d
0 dimensions, endowed with a warp factor e
2γ depending on the distance l from the string center. All possible regular solutions of the field equations are classified by the behavior of the warp
factor and the extradimensional circular radius r(l). Solutions with r → ∞ and r → const > 0 as l → ∞ are interpreted in terms of thick brane-world models. Solutions with r → 0 as l → l
c > 0, i.e., those with a second center, are interpreted as either multibrane systems (which are appropriate for large enough
distances l
c between the centers) or as Kaluza-Klein-type configurations with extra dimensions invisible due to their smallness. In the
case of the Mexican-hat symmetry-breaking potential, we build the full map of regular solutions on the (ɛ, Γ) parameter plane,
where ɛ acts as an effective cosmological constant and Γ characterizes the gravitational field strength. The trapping properties
of candidate brane worlds for test scalar fields are discussed. Good trapping properties for massive fields are found for
models with increasing warp factors. Kaluza-Klein-type models are shown to have nontrivial warp factor behaviors, leading
to matter particle mass spectra that seem promising from the standpoint of hierarchy problems.
The text was submitted by the authors in English. 相似文献
8.
Kinetic, spectral, intensity, angular, and polarization studies of resonant two-photon absorption (RTPA) in β-CdP2 have been carried out. RTPA was observed with 2.60 eV total energy of the two quanta. It was found that RTPA occurs through
a real intermediated level which lies in the forbidden band at a depthE=0.86 eV. The transverse electron relaxation time during RTPA, the cross section for absorption of laser radiation quanta
ind
3→C transitions, the equilibrium population of thed centers forn type doped samples, and the RTPA constant were determined to be 4.3 · 1014 sec, 1.25 · 10−17 cm, 0.95, and 0.028 cm/MW respectively.
Ukrainian State Pedagogical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 42, No. 1, pp.
21–26, January, 1999. 相似文献
9.
The effect of dimension index d
f
of the phonon spectrum, which is a structural characteristic in continual models, on the stability of states of condensed
media is considered in the Einstein and Debye approximations. The estimate of the phase state stability is based on the Lindemann
criterion generalized to arbitrary values of 0 ≤ d
f
≤ ∞. The problem of variation of physical characteristic of a substance by controlling the structure of its phonon spectrum
is considered by analyzing the possibility of obtaining molecular hydrogen in the superfluid state. The Einstein and Debye
models as applied to the problem on the dynamics of atomic oscillations are compared, and the divergence of the latter model
for fractal dimensions d
f
< 2 of the phonon spectrum is demonstrated, as well as the incompatibility of the Debye model at high temperatures and the
model of a classical oscillator for all dimensions except d
f
→ ∞. 相似文献
10.
Nathalie Besson Maarten Boonekamp Esben Klinkby Sascha Mehlhase Troels Petersen 《The European Physical Journal C - Particles and Fields》2008,57(3):627-651
We present a study of the LHC sensitivity to the W boson mass based on simulation studies. We find that both experimental and phenomenological sources of systematic uncertainties
can be strongly constrained with Z measurements: the lineshape, dσ
Z
/dm, is robustly predicted, and its analysis provides an accurate measurement of the detector resolution and absolute scale,
while the differential cross-section analysis, d2
σ
Z
/dydp
T
, absorbs the strong interaction uncertainties. A sensitivity δ
m
W
∼7 MeV for each decay channel (W→e
ν, W→μ
ν), and for an integrated luminosity of 10 fb−1, appears as a reasonable goal. 相似文献
11.
Chuan-Jia Shan Ji-Bing Liu Tang-Kun Liu Yan-Xia Huang Hong Li 《International Journal of Theoretical Physics》2009,48(5):1516-1522
In this paper, we propose a scheme for the controlled teleportation of an arbitrary two-atom entangled state |φ〉12=a|gg〉12+b|ge〉12+c|eg〉12+d|ee〉12 in driven cavity QED. An arbitrary two-atom entangled state can be teleported perfectly with the help of the cooperation
of the third side by constructing a three-atom GHZ entangled state as the controlled channel. This scheme does not involve
apparent (or direct) Bell-state measurement and is insensitive to the cavity decay and the thermal field. The probability
of the success in our scheme is 1.0. 相似文献
12.
T. V. Dudnikova 《Russian Journal of Mathematical Physics》2006,13(2):123-130
We consider the dynamics of a harmonic crystal in n dimensions with d components, where d and n are arbitrary, d, n ⩾ 1. The initial data are given by a random function with finite mean energy density which also satisfies a Rosenblatt-or
Ibragimov-type mixing condition. The random function is close to diverse space-homogeneous processes as x
n
→ ±∞, with the distributions μ±. We prove that the phase flow is mixing with respect to the limit measure of statistical
solutions.
Partially supported by RFBR under grant no. 06-01-00096. 相似文献
13.
The aim of the present work is to show how, using the differential calculus associated to Dirichlet forms, it is possible
to construct non-trivial Fredholm modules on post critically finite fractals by regular harmonic structures (D, r). The modules are (d
S
, ∞)–summable, the summability exponent d
S
coinciding with the spectral dimension of the generalized Laplacian operator associated with (D, r). The characteristic tools of the noncommutative infinitesimal calculus allow to define a d
S
-energy functional which is shown to be a self-similar conformal invariant.
Thiswork has been supported by the project “Teoria ellittica e forme di Dirichlet su spazi frattali” G.N.A.M.P.A. 2008 and
by the G.R.E.F.I.-G.E.N.C.O. French-Italian Research Group. 相似文献
14.
I. D. Morris 《Journal of statistical physics》2007,126(2):315-324
Let Σ
A
be a finitely primitive subshift of finite type over a countable alphabet. For suitable potentials f : Σ
A
→ ℝ we can associate an invariant Gibbs equilibrium state μ
tf
to the potential tf for each t ≥ 1. In this note, we show that the entropy h(μ
tf
) converges in the limit t→ ∞ to the maximum entropy of those invariant measures which maximize ∫ f
dμ. We further show that every weak-* accumulation point of the family of measures μ
tf
has entropy equal to this value. This answers a pair of questions posed by O. Jenkinson, R. D. Mauldin and M. Urbański. 相似文献
15.
We study the stationary distribution of the standard Abelian sandpile model in the box Λn = [-n, n]
d
∩ ℤ
d
for d≥ 2. We show that as n→ ∞, the finite volume stationary distributions weakly converge to a translation invariant measure on allowed sandpile configurations
in ℤ
d
. This allows us to define infinite volume versions of the avalanche-size distribution and related quantities. The proof is
based on a mapping of the sandpile model to the uniform spanning tree due to Majumdar and Dhar, and the existence of the wired
uniform spanning forest measure on ℤ
d
. In the case d > 4, we also make use of Wilson’s method.
An erratum to this article is available at . 相似文献
16.
Quantum-chemical calculations for series of porphin (H2P) and porphyrazine (H2PA) derivatives whose molecules contain a 3,4-annulated five-membered heteroaromatic ring of pyrrole, furan, and thiophene
as well as 1,2,5-triazole, 1,2,5-oxadiazole, and 1,2,5-thiadiazole have been carried out by the AM1 and INDO/Sm methods (m
means “modified parametrization”). As follows from the unrestricted Hartree-Fock AM1 calculations, the ground state energy
of the a isomer is lower than that of the b isomers for all compounds, the a and b isomers being NH isomers with the additional five-membered ring fused to a pyrrolenine or pyrrole ring, respectively. Condensation
of the five-membered ring for the b isomers of the H2P derivatives is shown to extend the main conjugation path from 18-membered to 21-membered cyclopolyene. However, the 18-membered
cyclopolyene for the a isomers of the H2P derivatives and 16-membered cyclopolyene for both isomers of the H2PA derivatives prove to be isolated from the five-membered ring carrying six π-electrons. Based on INDO/Sm computations of
electronic absorption spectra of the H2P and H2PA derivatives, it is shown that the Qx level of the a isomers is sensitive to the nature of the annulated ring whereas the Qy level is practically not shifted. On the contrary, the Qx level of the b isomers is relatively insensitive to the nature of the annulated ring while the Qy level decreases monotonously in the H2P and H2PA series, being the first excited state level for the majority of the derivatives (X is along the NH-HN axis; Y, perpendicular
to it). The electronic absorption spectra at the border of the visible and near-UV regions are determined mainly by two high-intensity
G → Bx and G → By transitions for the H2P derivatives. However, four intense G → Bx, G → By, G → Nx, and G → Ny transitions are characteristic of the spectra of the H2PA derivatives.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 606–622, September–October, 2008. 相似文献
17.
Hironobu Sakagawa 《Journal of statistical physics》2006,124(5):1255-1274
The main aim of this paper is to discuss the entropic repulsion of random interfaces between two hard walls. We consider the d (≥ 3)-dimensional Gaussian lattice field on ℝλ
N
, λ
N
= [−N, N]
d
∩ ℤ
d
and identify the repulsion of the field as N → ∞ under the condition that the field lies between two hard walls at the height level 0 and L in Λ
N
where L is large enough but finite. We also study the same problem for two layered interfaces case. 相似文献
18.
A real space renormalization group approach with two-terminal clusters is proposed for the calculation of the specific heat and spontaneous magnetization (for all temperatures) of the nearest-neighbour spin –1/2 Ising ferromagnet in simple cubic and hypercubic lattices. For arbitrary temperatures only small clusters (renormalization expansion factorb=2,3 ford=3 andb=2 ford=4) are considered: they lead to reasonable values for the critical points, exponents and amplitudes, to a thermal behaviour of the spontaneous magnetization which is already quite close to what is expected (from series results for example) but to a thermal behaviour of the specific heat which is not yet very close to what is expected. The global results improve whenb increases from 2 to 3. The drastic effect (on the specific heat) of an apparently innocuous approximation is exhibited. The discussion of theT0 andT limits is performed and theexact behaviours of the free and internal energies and the specific heat are obtained for sufficiently large values ofb andall dimensionalities.On leave of absence from Laboratorio de Física Teórica. Departamento de Física, Universidad Nactional de La Plata, CC No. 67 (1900), La Plata, Argentina. 相似文献
19.
We consider corrections to scaling within an approximate theory developed by Mazenko for nonconserved order parameter in the
limit of low (d → 1) and high (d → ∞) dimensions. The corrections to scaling considered here follows from the departures of the initial condition from the
scaling morphology. Including corrections to scaling, the equal time correlation function has the form: C(r, t) = f
0(r/L)+L
−ω
f
1(r/L)+…, where L is a characteristic length scale (i.e. domain size). The correction-to-scaling exponent ω and the correction-to-scaling functions f
1(x) are calculated for both low and high dimensions. In both dimensions the value of ω is found to be ω = 4 similar to 1D Glauber model and OJK theory (the theory developed by Ohta, Jasnow and Kawasaki). 相似文献
20.
Hyun Seok Yang 《The European Physical Journal C - Particles and Fields》2009,64(3):445-457
We map noncommutative (NC) U(1) gauge theory on ℝ
C
d
×ℝ
NC
2n
to U(N→∞) Yang–Mills theory on ℝ
C
d
, where ℝ
C
d
is a d-dimensional commutative spacetime while ℝ
NC
2n
is a 2n-dimensional NC space. The resulting U(N) Yang–Mills theory on ℝ
C
d
is equivalent to that obtained by the dimensional reduction of (d+2n)-dimensional U(N) Yang–Mills theory onto ℝ
C
d
. We show that the gauge-Higgs system (A
μ
,Φ
a
) in the U(N→∞) Yang–Mills theory on ℝ
C
d
leads to an emergent geometry in the (d+2n)-dimensional spacetime whose metric was determined by Ward a long time ago. In particular, the 10-dimensional gravity for
d=4 and n=3 corresponds to the emergent geometry arising from the 4-dimensional N=4{\mathcal{N}}=4 vector multiplet in the AdS/CFT duality. We further elucidate the emergent gravity by showing that the gauge-Higgs system
(A
μ
,Φ
a
) in half-BPS configurations describes self-dual Einstein gravity. 相似文献