The Tate Kernel of the Number Field Q (-3)

A complete characterization of Tate kernel of the number field Q (-3) is given.Our method can also be used in other fields.

The Problem on Class Numbers of Quadratic Number Fields

It is a survey of the problem on class numbers of quadratic number fields.

On Elliptic Curves with Everywhere Good Reduction over Certain Number Fields

We prove the existence and nonexistence of elliptic curves having good reduction everywhere over certain real quadratic fields Q(m) for m≤200. These results of computations give best-possible data including structures of Mordell-Weil groups over some real quadratic fields via two-descent. We also prove similar results for the case of certain cubic fields. Especially, we give the first example of elliptic curve having everywhere good reduction over a pure cubic field using our method.

Cryptography on elliptic curves over p-adic number fields

In this paper we introduce a cryptosystem based on the quotient groups of the group of rational points of an elliptic curve defined over p-adic number field. Some additional parameters are taken in this system, which have an advantage in performing point multiplication while keeping the security of ECC over finite fields. We give a method to select generators of the cryptographic groups, and give a way to represent the elements of the quotient groups with finitely bounded storage by establishing a bijection between these elements and their approximate coordinates. The addition formula under this representation is also presented.

Elliptic curves and their torsion subgroups over number fields of type (2,2,…,2)

Suppose that E：y2=x(x+M)(x+N) is an elliptic curve, where M<N arerational numbers (≠0,±1) and are relatively prime. Let K be a number field of type (2，…，2) with degree 2n. For arbitraryn, the structure of the torsion subgroup E(K)tors of the K-rational points (Mordell group) of E is completely determined here. Explicitly given are the classification, criteria and parameterization, as well as the groups E(K)tors themselves. The order of E(K)tors is also proved to be a power of 2 for any n. Besides, for any elliptic curve E over any number field F, it is shown that E(L)tors=E(F)tors holds for almost all extensions L/F of degree p(a prime number). These results have remarkably developed the recent results by Kwon about torsion subgroups over quadratic fields.

Fundamental Unit System and Class Number for Real Number Fields of Type (2,2,2)

Let k=Q((D 2+md)(D 2+nd)(D 2+rd)), this paper proves firstly that the fundamental unit of k is ε=((D 2+md)(D 2+nd)+D 2(D 2+rd)) 2/(|mn|d 2), where D,d,m,n, and r are rational integers satisfying certain conditions. Consequently, we describe the fundamental unit system of K=Q(D 2+md,D 2+nd,D 2+rd) explicitly by the fundamental unit of all the quadratic subfields and the class number h K explicitly by the class numbers of all the quadratic subfields. We also provide the fundamental unit system of some fields of (2,2) type.

On the Number of Integral Ideals in Two Different Quadratic Number Fields

Let K be an algebraic number field of finite degree over the rational field ~, and aK （n） the number of integral ideals in K with norm n. When K is a Galois extension over Q, many authors contribute to the integral power sums of aK（n）,This paper is interested in the distribution of integral ideals concerning different number fields. The author is able to establish asymptotic formulae for the convolution sumwhere K1 and K2 are two different quadratic fields.

A Note on the Behaviour of the Number Field Sieve in the Medium Prime Case: Smoothness of Norms

As we examine the behaviour of the number field sieve(NFS) in the medium prime case, we notice various patterns that can be exploited to improve the running time of the sieving stage. The contributions of these observations to the computational mathematics community are twofold. Firstly, we clarify the understanding of the true practical effectiveness of the algorithm. Secondly, we propose a test for a better choice of the polynomials used in the NFS. These results are of particular interest to cryptographers as the run-time of the NFS directly determines the security level of some discrete logarithm problem based protocols.

A new zeta function for number fields

According to the idea of class field theory, the possible absolutely normal number fieldsare restricted in nature by the arithmetical properties of rational number field .Becausethe fundamental arithmetical property of is the distributive law of the prime numbers,

VECTOR BUNDLE, KILLING VECTOR FIELD AND PONTRYAGIN NUMBERS

Let E be a vector bundle over a compact Riemannian manifold M. We construct a natural metric on the bundle space E and discuss the relationship between the killing vector fields of E and M. Then we give a proof of the Bott-Baum-Cheeger Theorem for vector bundle E.

Congruences for the class numbers of real cyclic sextic number fields

LetK 6 be a real cyclic sextic number field, andK 2,K 3 its quadratic and cubic subfield. Leth(L) denote the ideal class number of fieldL. Seven congruences forh - =h (K 6)/(h(K 2)h(K 3)) are obtained. In particular, when the conductorf 6 ofK 6 is a primep, $Ch^ - \equiv B\tfrac{{p - 1}}{6}B\tfrac{{5(p - 1)}}{6}(\bmod p)$ , whereC is an explicitly given constant, andB n is the Bernoulli number. These results on real cyclic sextic fields are an extension of the results on quadratic and cyclic quartic fields.

Criteria of Class Number h(K)=1 for Real Quadratic Number Fields

For real quadratic fields K, especially for fields K of ERD-type, a series of criteria of ideal class numbers h(K)=1 and h(K)】1 will be given via results of Diophantine equations in [1] and continued fraction theory. The problem of class numbers of real quadratic fields, after Gauss’conjecture, has been studied. For example, Lu Hong-wen

Relative Integral Bases of Number Fields of Type (q^s,q^s,…,q^s)

Let K be an abelian number field, and let K_G be its genus field. A simple construction of K_G was given in Ref. [1]. We here give a further description of K_G, which determines the conductor f(K) and discriminant D(K). And, using these results. we prove that an extension L/K of type (q^s, q^s,…, q^s) has a relative integral basis under some conditions. Suppose that L is any algebraic number field containing K as a subfield. Since

On the least primitive root in number fields

Let K be an algebraic number field and OK its ring of integers.For any prime ideal p,the group(OK/p) of the reduced residue classes of integers is cyclic.We call any element of a generator of the group(OK/p) a primitive root modulo p.Stimulated both by Shoup's bound for the rational improvement and Wang and Bauer's generalization of the conditional result of Wang Yuan in 1959,we give in this paper a new bound for the least primitive root modulo a prime ideal p under the Grand Riemann Hypothesis for algebraic number field.Our results can be viewed as either the improvement of the result of Wang and Bauer or the generalization of the result of Shoup.

A COMPLETE DETERMINATION OF THE CUBIC CYCLIC EXTENSION FIELDS OF NUMBER FIELDS

The fundamental topic of algebraic number theory is to determine all Galois extension fields of a number field. The class field theory determines all Abelian extension fields of a number field on theoretical, but it is not concrete. The author has studied the arithmetic properties of cubic cyclic extensions of number fields in [1, 2]. In this report, we determine all cubic cyclic extension fields of any number field K.

Time evolution of a squeezed chaotic field in an amplitude damping channel when used as a generating field for a squeezed number state

We investigate how an optical squeezed chaotic field（SCF） evolves in an amplitude dissipation channel. We have used the integration within ordered product of operators technique to derive its evolution law. We also show that the density operator of SCF can be viewed as a generating field of the squeezed number state.

Relationship between the Sunspot Number and Solar Polar Field by Wavelet-Based Multifractal Analysis

There is increasing interest in finding the relation between the sunspot number (SSN) and solar polar field. In general, fractal properties may be observed in the time series of the dynamics of complex systems, such as solar activity and climate. This study investigated the relations between the SSN and solar polar field by performing a multifractal analysis. To investigate the change in multifractality, we applied a wavelet transform to time series. When the SSN was maximum and minimum, the SSN showed monofractality or weak multifractality. The solar polar field showed weak multifractality when that was maximum and minimum. When the SSN became maximum, the fractality of the SSN changed from multifractality to monofractality. The multifractality of SSN became large before two years of SSN maximum, then that of the solar polar field became large and changed largely. It was found that the change in SSN triggered the change in the solar polar field. Hence, the SSN and solar polar field were closely correlated from the view point of fractals. When the maximum solar polar field before the maximum SSN was larger, the maximum SSN of the next cycle was larger. The formation of the magnetic field of the sunspots was correlated with the solar polar field.

Quadratic Number Fields with Class Numbers Divisible by a Prime q

Let q 5 be a prime number. Let k d=() be a quadratic number field, where d =--gqq(1)2(1) ---qqqquwuq12((1)+). Then the class number of k is divisible by q for certain integers u,w. Conversely, assume W / k is an unramified cyclic extension of degree q (which implies the class number of k is divisible by q), and W is the splitting field of some irreducible trinomial f(X) = XqaXb with integer coefficients, k Df=(())with D(f) the discriminant of f(X). Then f(X) must be of the form f(X) = Xquq2wXuq1 in a cer-tain sense where u,w are certain integers. Therefore, k d=() with d =-----qqqqqquwuq(1)122(1)((1)+). Moreover, the above two results are both generalized for certain kinds of general polynomials.

STRONG LAW OF LARGE NUMBERS AND ASYMPTOTIC EQUIPARTITION PROPERTY FOR NONSYMMETRIC MARKOV CHAIN FIELDS ON CAYLEY TREES

Some strong laws of large numbers for the frequencies of occurrence of states and ordered couples of states for nonsymmetric Markov chain fields （NSMC） on Cayley trees are studied. In the proof, a new technique for the study of strong limit theorems of Markov chains is extended to the case of Markov chain fields, The asymptotic equipartition properties with almost everywhere （a,e.） convergence for NSMC on Cayley trees are obtained,

STRONG LAW OF LARGE NUMBERS AND SHANNON-MCMILLAN THEOREM FOR MARKOV CHAINS FIELD ON CAYLEY TREE

This paper studies the strong law of large numbers and the Shannom-McMillan theorem for Markov chains field on Cayley tree. The authors first prove the strong law of large number on the frequencies of states and orderd couples of states for Markov chains field on Cayley tree. Then they prove the Shannon-McMillan theorem with a.e. convergence for Markov chains field on Cayley tree. In the proof, a new technique in the study the strong limit theorem in probability theory is applied.