THE famous Cohen-Lenstra heuristics aroused wide insterest and research. Here for a certaintype of real quadratic fields with elements P of potential order p in their ideal classes, modifi-cations of the Cohen-Lenstra...THE famous Cohen-Lenstra heuristics aroused wide insterest and research. Here for a certaintype of real quadratic fields with elements P of potential order p in their ideal classes, modifi-cations of the Cohen-Lenstra heuristics for the probability that the class number h is a multipleof p, and the probability that P is of order p, are presented. Via a quite large amount ofcomputations, it was found that both of these probability predictions agree fairly well with thenumerical data.展开更多
We investigate arithmetic properties of certain subsets of square-free positive integers and obtain in this way some results concerning the class number h（d） of the real quadratic field Q（√d）. In particular, we g...We investigate arithmetic properties of certain subsets of square-free positive integers and obtain in this way some results concerning the class number h（d） of the real quadratic field Q（√d）. In particular, we give a new proof of the result of Hasse, asserting that in this case h（d） = 1 is possible only if d is of the form p, 2q or qr. where p.q. r are primes and q≡r≡3（mod 4）.展开更多
In this paper, the theory of continued fractions of algebraic functions will be used to give a general theorem on lower bounds for class numbers of real quadratic function fields K=k(D). The bounds are given more expl...In this paper, the theory of continued fractions of algebraic functions will be used to give a general theorem on lower bounds for class numbers of real quadratic function fields K=k(D). The bounds are given more explicitly for six types of real quadratic function fields. As a consequence, six classes of real quadratic function fields with ideal class number greater than one are given.[展开更多
A necessary and sufficient condition is given for the ideal class group H( m } of a real quadratic field Q (m)to contain a cyclic subgroup of order n.Some criteria satisfying the condition are also obtained.And eight ...A necessary and sufficient condition is given for the ideal class group H( m } of a real quadratic field Q (m)to contain a cyclic subgroup of order n.Some criteria satisfying the condition are also obtained.And eight types of such fields are proved to have this property,e.g.fields with m=(zn+t+12)+4t(with t|zn-1),which contains the well-known fields with m=4zn+1 and m=z2n+4 as special cases.展开更多
Series of results about ideal class groups H （m） and class numbers h （m） of real quadratic fields Q (m<sup>1/2</sup>) can be obtained from [6]. Some of them will be shown in this note. We denote by C&l...Series of results about ideal class groups H （m） and class numbers h （m） of real quadratic fields Q (m<sup>1/2</sup>) can be obtained from [6]. Some of them will be shown in this note. We denote by C<sub>n</sub> =Z/nZ the cyclic group of order n. Let m ∈ Z denote a square free positive integer, and let z<sub>1</sub>, z, t ∈Z be arbitrary integers with z<sub>1</sub> odd and t】0.展开更多
The fact is studied that the ideal class numbers h of types of real quadratic fields usually contain a fixed prime number p as a factor, and the reason is found to be existing there a kind of prime ideals whose p th p...The fact is studied that the ideal class numbers h of types of real quadratic fields usually contain a fixed prime number p as a factor, and the reason is found to be existing there a kind of prime ideals whose p th powers are principal. A modification of the Cohen Lenstra Heuristics for the probability that in this situation the class number h is actually a multiple of p then is presented: Prob (p|h)=1-(1-p -1 )(1-p -2 ).... This idea is also extended to predict the probability that the class P represented by the above prime ideal is actually of order p : Prob (o(P)=p) =1/p. Both of these predictions agree fairly well with the numerical data.展开更多
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, ...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.展开更多
文摘THE famous Cohen-Lenstra heuristics aroused wide insterest and research. Here for a certaintype of real quadratic fields with elements P of potential order p in their ideal classes, modifi-cations of the Cohen-Lenstra heuristics for the probability that the class number h is a multipleof p, and the probability that P is of order p, are presented. Via a quite large amount ofcomputations, it was found that both of these probability predictions agree fairly well with thenumerical data.
文摘We investigate arithmetic properties of certain subsets of square-free positive integers and obtain in this way some results concerning the class number h（d） of the real quadratic field Q（√d）. In particular, we give a new proof of the result of Hasse, asserting that in this case h（d） = 1 is possible only if d is of the form p, 2q or qr. where p.q. r are primes and q≡r≡3（mod 4）.
文摘In this paper, the theory of continued fractions of algebraic functions will be used to give a general theorem on lower bounds for class numbers of real quadratic function fields K=k(D). The bounds are given more explicitly for six types of real quadratic function fields. As a consequence, six classes of real quadratic function fields with ideal class number greater than one are given.[
基金Project supported by the National Natural Science Foundation of China.
文摘A necessary and sufficient condition is given for the ideal class group H( m } of a real quadratic field Q (m)to contain a cyclic subgroup of order n.Some criteria satisfying the condition are also obtained.And eight types of such fields are proved to have this property,e.g.fields with m=(zn+t+12)+4t(with t|zn-1),which contains the well-known fields with m=4zn+1 and m=z2n+4 as special cases.
文摘Series of results about ideal class groups H （m） and class numbers h （m） of real quadratic fields Q (m<sup>1/2</sup>) can be obtained from [6]. Some of them will be shown in this note. We denote by C<sub>n</sub> =Z/nZ the cyclic group of order n. Let m ∈ Z denote a square free positive integer, and let z<sub>1</sub>, z, t ∈Z be arbitrary integers with z<sub>1</sub> odd and t】0.
文摘The fact is studied that the ideal class numbers h of types of real quadratic fields usually contain a fixed prime number p as a factor, and the reason is found to be existing there a kind of prime ideals whose p th powers are principal. A modification of the Cohen Lenstra Heuristics for the probability that in this situation the class number h is actually a multiple of p then is presented: Prob (p|h)=1-(1-p -1 )(1-p -2 ).... This idea is also extended to predict the probability that the class P represented by the above prime ideal is actually of order p : Prob (o(P)=p) =1/p. Both of these predictions agree fairly well with the numerical data.
基金Project supported by the National Natural Science Foundation of China (Grant No. 19771052).
文摘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.
