共查询到20条相似文献,搜索用时 31 毫秒
1.
For a germ of a smooth map f from
\mathbb Kn{{\mathbb K}^n} to
\mathbb Kp{{\mathbb K}^p} and a subgroup GWq{{{G}_{\Omega _q}}} of any of the Mather groups G for which the source or target diffeomorphisms preserve some given volume form Ω
q
in
\mathbb Kq{{\mathbb K}^q} (q = n or p) we study the GWq{{{G}_{\Omega _q}}} -moduli space of f that parameterizes the GWq{{{G}_{\Omega _q}}} -orbits inside the G-orbit of f. We find, for example, that this moduli space vanishes for GWq = AWp{{{G}_{\Omega _q}} ={{\mathcal A}_{\Omega _p}}} and A{{\mathcal A}}-stable maps f and for GWq = KWn{{{G}_{\Omega _q}} ={{\mathcal K}_{\Omega _n}}} and K{{\mathcal K}}-simple maps f. On the other hand, there are A{{\mathcal A}}-stable maps f with infinite-dimensional AWn{{{\mathcal A}_{\Omega _n}}} -moduli space. 相似文献
2.
S. A. Stasyuk 《Ukrainian Mathematical Journal》2011,63(4):638-645
We obtain an exact-order estimate for the best m-term approximation of the classes B¥, qr B_{\infty, \theta }^r of periodic functions of many variables by polynomials in the Haar system in the metric of the space L
q
, 1 < q < ∞. 相似文献
3.
Dragan Stankov 《Monatshefte für Mathematik》2010,88(1):115-131
We investigate the class of ± 1 polynomials evaluated at a real number q> 1 defined as:
A(q)={e0+e1q+?+ek qk : ei ? {-1,1}}A(q)=\{\epsilon_0+\epsilon_1q+\cdots+\epsilon_k q^k : \epsilon_i\in\{-1,1\}\} 相似文献
4.
Lasha Ephremidze Gigla Janashia Edem Lagvilava 《Journal of Fourier Analysis and Applications》2011,17(5):976-990
It is proved that if positive definite matrix functions (i.e. matrix spectral densities) S
n
, n=1,2,… , are convergent in the L
1-norm, ||Sn-S||L1? 0\|S_{n}-S\|_{L_{1}}\to 0, and ò02plogdetSn(eiq) dq?ò02plogdetS(eiq) dq\int_{0}^{2\pi}\log \mathop{\mathrm{det}}S_{n}(e^{i\theta})\,d\theta\to\int_{0}^{2\pi}\log \mathop{\mathrm{det}}S(e^{i\theta})\,d\theta, then the corresponding (canonical) spectral factors are convergent in L
2, ||S+n-S+||L2? 0\|S^{+}_{n}-S^{+}\|_{L_{2}}\to 0. The formulated logarithmic condition is easily seen to be necessary for the latter convergence to take place. 相似文献
5.
In this paper we introduce and study a family An(q)\mathcal{A}_{n}(q) of abelian subgroups of GLn(q){\rm GL}_{n}(q) covering every element of GLn(q){\rm GL}_{n}(q). We show that An(q)\mathcal{A}_{n}(q) contains all the centralizers of cyclic matrices and equality holds if q>n. For q>2, we obtain an infinite product expression for a probabilistic generating function for |An(q)||\mathcal{A}_{n}(q)|. This leads to upper and lower bounds which show in particular that
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