共查询到20条相似文献,搜索用时 15 毫秒
1.
Robert Schrader 《Communications in Mathematical Physics》1976,49(2):131-153
We propose a constructive approach to
4
4
. It is based on formulating the
4
4
theory as an implicit function problem using multiplicative renormalization. For the corresponding lattice formulation we reduce the problem to verifying three conjectures. One conjecture is a regularity condition. The remaining two concern properties of the classical Ising ferromagnet, one of which we discuss in the frame work of critical point analysis. 相似文献
2.
3.
《Proceedings of the Combustion Institute》2023,39(1):85-94
Real biodiesel fuels are mixtures comprising many high molecular weight components, making it a challenge to predict their combustion chemistry with detailed kinetic models. Our group previously proposed a functional-group approach (FGMech) to model the combustion chemistry of real gasoline and jet fuels; this approach has now been extended to model real biodiesel combustion and mixtures with petroleum fuels. As in our previous work, a decoupling philosophy is adopted for construction of the model. A lumped reaction mechanism describes the (oxidative) pyrolysis of fuels, while a detailed base chemistry model represents the oxidation of key pyrolysis intermediates. However, due to the presence of the ester group, several oxygenated species are identified as additional primary products and incorporated into the lumped reaction steps. In addition to the lumped reactions initiated by unimolecular decomposition and H-atom abstraction reactions, a lumped H-atom addition-elimination reaction is also incorporated as a new reaction class to account for the presence of double bonds. Stoichiometric parameters are obtained based on a multiple linear regression (MLR) model, which establishes relationships between the fuel's functional group distributions and the stoichiometric parameters of the lumped reactions. Global rate constants are developed from consistent rate rules obtained from pure fuels. New pyrolysis experimental data for methyl pentanoate/methyl nonanoate and methyl heptanoate/n-heptane mixtures (50%/50% in mol) are obtained in a jet-stirred reactor at atmospheric pressure. In general, kinetic models developed using the FGMech approach can reasonably reproduce all the validation targets obtained in this work, as well as those in the literature, confirming that functional-group-modeling is a promising approach to simulate combustion behavior of diesel/biodiesel surrogate fuels and real biodiesels. 相似文献
4.
In this paper, we present some preliminary studies on using a Robinson wiggler to reduce the horizontal beam emittance in the Hefei Light Source Ⅱ (HLS-Ⅱ) storage ring. A proof-of-principle lattice demonstrates that it is possible to reduce its emittance by 50% with a 2-meter long wiggler. This encouraging result suggests a feasible option to significantly improve the machine performance at a relatively low cost. 相似文献
5.
Rolf Schilling 《Zeitschrift für Physik B Condensed Matter》1997,103(3):463-468
We reinvestigate the mode coupling approach to the central peak which occurs in the vicinity of a structural phase transition at T c. For a scalar ? 4-model it is shown that the use of renormalized vertices leads to quite different results compared to recent calculations with bare vertices. Particularly, we prove that the latter are obtained in leading order of the anharmonicity constant of the on-site potential from a perturbational treatment of the renormalized vertices. Again, this mode coupling approach may yield a dynamical transition at a temperature T c'(≥ T c) at which the dynamics becomes nonergodic, i.e. a central peak occurs. For a ? 4- model with infinite range interactions our theoretical predictions are consistent with numerical results. Furthermore, if the fluctuations in the vicinity of Tc are Gaussian, no dynamical transition occurs above Tc. Therefore the temperature T 0'obtained from the Ginzburg criterion sets an upper bound for T c'. If a dynamical transition occurs, it is shown that the nonergodicity parameter as function of wave vector q and temperature T follows from an universal master function. 相似文献
6.
The Heisenberg spin chain is considered in ? 4 model approximation. Quantum corrections to classical solutions of the one-dimensional ? 4 model within the correspondent physics are evaluated with account of rest d-1 dimensions of a d-dimensional theory. A quantization of the model is considered in terms of spacetime functional integral. The generalized zeta-function formalism is used to renormalize and evaluate the functional integral and quantum corrections to energy in a quasiclassical approximation. The results are applied to appropriate conditions of the spin chain model and its dynamics, for which elementary solutions, energy and the quantum corrections are calculated. 相似文献
7.
David C. Brydges Jürg Fröhlich Alan D. Sokal 《Communications in Mathematical Physics》1983,91(2):141-186
We use Schwinger-Dyson equations combined with rigorous “perturbation-theoretic” correlation inequalities to give a new and extremely simple proof of the existence and nontriviality of the weakly-coupled continuum ? 2 4 and ? 3 4 quantum field theories, constructed as subsequence limits of lattice theories. We prove an asymptotic expansion to order λ or λ2 for the correlation functions and for the mass gap. All Osterwalder-Schrader axioms are satisfied except perhaps Euclidean (rotation) invariance. 相似文献
8.
9.
Using Gawedzki and Kupiainen's rigorous block spin transformation method, we study critical phenomena in 4 spin systems in four dimensions. In Part I of this work we investigate in detail the renormalization group trajectory of the system not exactly at the critical point. 相似文献
10.
Hiroshi Watanabe 《Journal of statistical physics》1989,54(1-2):171-190
A block spin approach to the Euclidean
4 field theory in three dimensions is proposed by using the three-dimensional version of Gawedzki and Kupiainen's block spin transformation method. The lattice
3
4
model recovers the rotation invariance in the continuum limit, when the coupling constant is small. 相似文献
11.
Marius van der Put 《Journal of Nonlinear Mathematical Physics》2013,20(4):165-177
The methods of [vdP-Sa, vdP1, vdP2] are applied to the fourth Painlevé equation. One obtains a Riemann–Hilbert correspondence between moduli spaces of rank two connections on ?1 and moduli spaces for the monodromy data. The moduli spaces for these connections are identified with Okamoto–Painlevé varieties and the Painlevé property follows. For an explicit computation of the full group of Bäcklund transformations, rank three connections on ?1 are introduced, inspired by the symmetric form for PIV, studied by M. Noumi and Y. Yamada. 相似文献
12.
I. M. Suslov 《JETP Letters》2000,71(6):217-221
An algorithm is proposed for the determination of the asymptotics of a sum of a perturbation series from the given values of its coefficients in the strong-coupling limit. When applied to the ?4 theory, the algorithm yields the β(g)∝g α behavior with α≈1 at large g for the Gell-Mann-Low function. 相似文献
13.
《Physics letters. [Part B]》2004,578(1-2):231-234
We find the leading RG logs in ϕ4 theory for any Feynman diagram with 4 external edges. We obtain the result in two ways. The first way is to calculate the relevant terms in Feynman integrals. The second way is to use the RG invariance based on the Lie algebra of graphs introduced by Connes and Kreimer. 相似文献
14.
《Physics letters. [Part B]》1987,188(3):383-387
New data have been obtained on a resonance in the ϕπ0 system, the C meson, which is formed in the π−p→ϕπ0n charge-exchange reaction. The experiment has been performed at the Serpukhov 70 GeV accelerator. The mass and the width of the resonance are measured to be M=1480±40 MeV, Γ=130±60 MeV. The production cross section is determined at a π− momentum of 32.5 GeV/c:σ(π−p→Cn)·BR(C→ϕπ0)=40±15nb. The C(1480) meson has an isospin I=1 and spin-parity JPC=1− −. It is strongly coupled to the ϕπ0 channel and is considered as a possible exotic meson. 相似文献
15.
We consider scattering for the equation (+m
2)+3=0 on four-dimensional Minkowski space. Form>0, one-to-one and onto wave operatorsW
±
:HH are known to exist for all 0, whereH denotes the Hilbert space of finite-energy Cauchy data. We prove that the maps (,u)W
±
(u) and (,u)(W
±
)–1 (u) are continuous from [0, )×H toH, and extend to real-analytic functions from an open neighborhood of {0}×H×{0}×H to the Hilbert spaceH
–1 of Cauchy data with Poincaré-invariant norm. Form=0, wave operatorsW
±
are known to exist as diffeomorphisms ofH for all 0, where hereH denotes the Hilbert space of finite Einstein energy Cauchy data. In this case we prove that the maps (,u)(W
±
) (u) and (,u)(W
±
)–1 (u) extend to real-analytic functions from a neighborhood of [0, )×H×H toH. 相似文献
16.
An analytical model for adding a space-dependent potential to the ? 4 field equation of motion is presented, by constructing a collective coordinate system for the solitary solutions of this model. The interaction of ? 4 solitons with a delta function potential barrier and also delta function potential well is investigated. Most of the characters of interaction are derived analytically while they are calculated by other models numerically. We will find that the behaviour of a solitary solution is like a point particle which is moved under the influence of a complicated effective potential. The effective potential is a function of the field initial conditions and also of parameters of the added potential. 相似文献
17.
《Physics letters. A》2003,307(4):233-238
We solve perturbatively the quantum elliptic Calogero–Sutherland model in the regime in which the quotient between the real and imaginary semiperiods of the Weierstrass function is small. 相似文献
18.
19.
José L. Soria 《Journal of statistical physics》1988,52(3-4):711-726
A collection of new and already known correlation inequalities is found for a family of two-component hypercubic
4 models, using techniques of duplicated variables, rotated correlation inequalities, and random walk representation. Among the interesting new inequalities are: rotated very special Dunlop-Newman inequality
1,x
2
;
1,z
2
+
2g
2
0, rotated Griffiths I inequality 1,x
1,y
;
1z
2
0, and anti-Lebowitz inequalityu
4
1111
>-0. 相似文献
20.
An approach of lidar measurements of ocean temperature through measuring the spectral linewidth of the backscattered Brillouin lines is presented. An empirical equation for the temperature as a function of Brillouin linewidth and salinity is derived. Theoretical results are in good agreement with the experimental data. The equation also reveals the dependence of the temperature on the salinity and Brillouin linewidth. It is shown that the uncertainty of the salinity has very little impact on the temperature measurement. The uncertainty of this temperature measurement methodology is approximately 0.02℃. 相似文献