• Title/Summary/Keyword: Omega theorem

Search Result 66, Processing Time 0.026 seconds

On the $Z_p$-extensions over $Q(sqrt{m})$

  • Kim, Jae-Moon
    • Communications of the Korean Mathematical Society
    • /
    • v.13 no.2
    • /
    • pp.233-242
    • /
    • 1998
  • Let $k = Q(\sqrt{m})$ be a real quadratic field. In this paper, the following theorems on p-divisibility of the class number h of k are studied for each prime pp. Theorem 1. If the discriminant of k has at least three distinct prime divisors, then 2 divides h. Theorem 2. If an odd prime p divides h, then p divides $B_{a,\chi\omega^{-1}}$, where $\chi$ is the nontrivial character of k, and $\omega$ is the Teichmuller character for pp. Theorem 3. Let $h_n$ be the class number of $k_n$, the nth layer of the $Z_p$-extension $k_\infty$ of k. If p does not divide $B_{a,\chi\omega^{-1}}$, then $p \notmid h_n$ for all $n \geq 0$.

  • PDF

EXISTENCE AND MULTIPLICITY RESULTS FOR SOME FOURTH ORDER SEMILINEAR ELLIPTIC PROBLEMS

  • Jin, Yinghua;Wang, Xuechun
    • Korean Journal of Mathematics
    • /
    • v.17 no.4
    • /
    • pp.473-480
    • /
    • 2009
  • We prove the existence and multiplicity of nontrivial solutions for a fourth order problem ${\Delta}^2u+c{\Delta}u={\alpha}u-{\beta}(u+1)^-$ in ${\Omega}$, ${\Delta}u=0$ and $u=0$ on ${\partial}{\Omega}$, where ${\lambda}_1{\leq}c{\leq}{\lambda}_2$ (where $({\lambda}_i)_{i{\geq}1}$ is the sequence of the eigenvalues of $-{\Delta}$ in$H_0^1({\Omega})$) and ${\Omega}$ is a bounded open set in $R^N$ with smooth boundary ${\partial}{\Omega}$. The results are proved by applying minimax arguments and linking theory.

  • PDF

EXISTENCE OF WEAK NON-NEGATIVE SOLUTIONS FOR A CLASS OF NONUNIFORMLY BOUNDARY VALUE PROBLEM

  • Hang, Trinh Thi Minh;Toan, Hoang Quoc
    • Bulletin of the Korean Mathematical Society
    • /
    • v.49 no.4
    • /
    • pp.737-748
    • /
    • 2012
  • The goal of this paper is to study the existence of non-trivial non-negative weak solution for the nonlinear elliptic equation: $$-div(h(x){\nabla}u)=f(x,u)\;in\;{\Omega}$$ with Dirichlet boundary condition in a bounded domain ${\Omega}{\subset}\mathbb{R}^N$, $N{\geq}3$, where $h(x){\in}L^1_{loc}({\Omega})$, $f(x,s)$ has asymptotically linear behavior. The solutions will be obtained in a subspace of the space $H^1_0({\Omega})$ and the proofs rely essentially on a variation of the mountain pass theorem in [12].

CONVEX POLYTOPES OF GENERALIZED DOUBLY STOCHASTIC MATRICES

  • Cho, Soo-Jin;Nam, Yun-Sun
    • Communications of the Korean Mathematical Society
    • /
    • v.16 no.4
    • /
    • pp.679-690
    • /
    • 2001
  • Doubly stochastic matrices are n$\times$n nonnegative ma-trices whose row and column sums are all 1. Convex polytope $\Omega$$_{n}$ of doubly stochastic matrices and more generally (R,S), so called transportation polytopes, are important since they form the domains for the transportation problems. A theorem by Birkhoff classifies the extremal matrices of , $\Omega$$_{n}$ and extremal matrices of transporta-tion polytopes (R,S) were all classified combinatorially. In this article, we consider signed version of $\Omega$$_{n}$ and (R.S), obtain signed Birkhoff theorem; we define a new class of convex polytopes (R,S), calculate their dimensions, and classify their extremal matrices, Moreover, we suggest an algorithm to express a matrix in (R,S) as a convex combination of txtremal matrices. We also give an example that a polytope of signed matrices is used as a domain for a decision problem. In this context of finite reflection(Coxeter) group theory, our generalization may also be considered as a generalization from type $A_{*}$ n/ to type B$_{n}$ D$_{n}$. n/.

  • PDF

NONTRIVIAL SOLUTIONS FOR AN ELLIPTIC SYSTEM

  • Nam, Hyewon;Lee, Seong Cheol
    • Korean Journal of Mathematics
    • /
    • v.23 no.1
    • /
    • pp.153-161
    • /
    • 2015
  • In this work, we consider an elliptic system $$\left{\array {-{\Delta}u=au+bv+{\delta}_1u+-{\delta}_2u^-+f_1(x,u,v) && in\;{\Omega},\\-{\Delta}v=bu+cv+{\eta}_1v^+-{\eta}_2v^-+f_2(x,u,v) && in\;{\Omega},\\{\hfill{70}}u=v=0{\hfill{90}}on\;{\partial}{\Omega},}$$, where ${\Omega}{\subset}R^N$ be a bounded domain with smooth boundary. We prove that the system has at least two nontrivial solutions by applying linking theorem.

PROPER RATIONAL MAP IN THE PLANE

  • Jeong, Moon-Ja
    • The Pure and Applied Mathematics
    • /
    • v.2 no.2
    • /
    • pp.97-101
    • /
    • 1995
  • In [6], the author studied the property of the Szeg kernel and had a result that if $\Omega$ is a smoothly bounded domain in C and the Szeg kernel associated with $\Omega$ is rational, then any proper holomorphic map from $\Omega$ to the unit disc U is rational. It leads to the study of the proper rational map of $\Omega$ to U. In this note, first we simplify the proof of the above result and prove an existence theorem of a proper rational map. Before we proceed to state our result, we must recall some preliminary facts.(omitted)

  • PDF

S-ASYMPTOTICALLY ω-PERIODIC MILD SOLUTIONS FOR THE SYSTEMS OF DIFFERENTIAL EQUATIONS WITH PIECEWISE CONSTANT ARGUMENT IN BANACH SPACES

  • Lee, Hyun Mork;Jang, Hyun Ho;Yun, Chan Mi
    • Journal of the Chungcheong Mathematical Society
    • /
    • v.31 no.1
    • /
    • pp.13-27
    • /
    • 2018
  • By using of the Banach fixed point theorem, the theory of a strongly continuous semigroup of operators and resolvent operator, we investigate the existence and uniqueness of S-asymptotically ${\omega}-periodic$ mild solutions for some differential (integrodifferential) equations with piecewise constant argument when specially ${\omega}$ is an integer.

NONTRIVIAL PERIODIC SOLUTION FOR THE SUPERQUADRATIC PARABOLIC PROBLEM

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
    • /
    • v.17 no.1
    • /
    • pp.53-66
    • /
    • 2009
  • We show the existence of a nontrivial periodic solution for the superquadratic parabolic equation with Dirichlet boundary condition and periodic condition with a superquadratic nonlinear term at infinity which have continuous derivatives. We use the critical point theory on the real Hilbert space $L_2({\Omega}{\times}(0 2{\pi}))$. We also use the variational linking theorem which is a generalization of the mountain pass theorem.

  • PDF

An existence of solutions for an infinte diffusion constant

  • Ham, Yoon-Mee
    • Bulletin of the Korean Mathematical Society
    • /
    • v.33 no.4
    • /
    • pp.631-638
    • /
    • 1996
  • The parabolic free boundary problem with Puschino dynamics is given by (see in [3]) $$ (1) { \upsilon_t = D\upsilon_{xx} - (c_1 + b)\upsilon + c_1 H(x - s(t)) for (x,t) \in \Omega^- \cup \Omega^+, { \upsilon_x(0,t) = 0 = \upsilon_x(1,t) for t > 0, { \upsilon(x,0) = \upsilon_0(x) for 0 \leq x \leq 1, { \tau\frac{dt}{ds} = C)\upsilon(s(t),t)) for t > 0, { s(0) = s_0, 0 < s_0 < 1, $$ where $\upsilon(x,t)$ and $\upsilon_x(x,t)$ are assumed continuous in $\Omega = (0,1) \times (0, \infty)$.

  • PDF

REPRESENTATION OF $L^1$-VALUED CONTROLLER ON BESOV SPACES

  • Jeong, Jin-Mun;Kim, Dong-Hwa
    • East Asian mathematical journal
    • /
    • v.19 no.1
    • /
    • pp.133-150
    • /
    • 2003
  • This paper will show that the relation (1.1) $$L^1({\Omega}){\subset}C_0(\bar{\Omega}){\subset}H_{p,q}$$ if 1/p'-1/n(1-2/q')<0 where p'=p/(p-1) and q'=q/(q-1) where $H_{p.q}=(W^{1,p}_0,W^{-1,p})_{1/q,q}$. We also intend to investigate the control problems for the retarded systems with $L^1(\Omega)$-valued controller in $H_{p,q}$.

  • PDF