scholarly journals The mean values of Dirichlet L-functions at integer points and class numbers of cyclotomic fields

1994 ◽  
Vol 134 ◽  
pp. 151-172 ◽  
Author(s):  
Masanori Katsurada ◽  
Kohji Matsumoto

Let q be a positive integer, and L(s, χ) the Dirichlet L-function corresponding to a Dirichlet character χ mod q. We putwhere χ runs over all Dirichlet characters mod q except for the principal character χ0.

2018 ◽  
Vol 14 (04) ◽  
pp. 1047-1054 ◽  
Author(s):  
László Tóth

Let [Formula: see text] be a Dirichlet character (mod [Formula: see text]) with conductor [Formula: see text]. In a quite recent paper Zhao and Cao deduced the identity [Formula: see text], which reduces to Menon’s identity if [Formula: see text] is the principal character (mod [Formula: see text]). We generalize the above identity by considering even functions (mod [Formula: see text]), and offer an alternative approach to prove. We also obtain certain related formulas concerning Ramanujan sums.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Alessandro Languasco

AbstractWe introduce a new algorithm, which is faster and requires less computing resources than the ones previously known, to compute the Euler–Kronecker constants $${\mathfrak {G}}_q$$ G q for the prime cyclotomic fields $$ {\mathbb {Q}}(\zeta _q)$$ Q ( ζ q ) , where q is an odd prime and $$\zeta _q$$ ζ q is a primitive q-root of unity. With such a new algorithm we evaluated $${\mathfrak {G}}_q$$ G q and $${\mathfrak {G}}_q^+$$ G q + , where $${\mathfrak {G}}_q^+$$ G q + is the Euler–Kronecker constant of the maximal real subfield of $${\mathbb {Q}}(\zeta _q)$$ Q ( ζ q ) , for some very large primes q thus obtaining two new negative values of $${\mathfrak {G}}_q$$ G q : $${\mathfrak {G}}_{9109334831}= -0.248739\dotsc $$ G 9109334831 = - 0.248739 ⋯ and $${\mathfrak {G}}_{9854964401}= -0.096465\dotsc $$ G 9854964401 = - 0.096465 ⋯ We also evaluated $${\mathfrak {G}}_q$$ G q and $${\mathfrak {G}}^+_q$$ G q + for every odd prime $$q\le 10^6$$ q ≤ 10 6 , thus enlarging the size of the previously known range for $${\mathfrak {G}}_q$$ G q and $${\mathfrak {G}}^+_q$$ G q + . Our method also reveals that the difference $${\mathfrak {G}}_q - {\mathfrak {G}}^+_q$$ G q - G q + can be computed in a much simpler way than both its summands, see Sect. 3.4. Moreover, as a by-product, we also computed $$M_q=\max _{\chi \ne \chi _0} \vert L^\prime /L(1,\chi ) \vert $$ M q = max χ ≠ χ 0 | L ′ / L ( 1 , χ ) | for every odd prime $$q\le 10^6$$ q ≤ 10 6 , where $$L(s,\chi )$$ L ( s , χ ) are the Dirichlet L-functions, $$\chi $$ χ run over the non trivial Dirichlet characters mod q and $$\chi _0$$ χ 0 is the trivial Dirichlet character mod q. As another by-product of our computations, we will provide more data on the generalised Euler constants in arithmetic progressions.


2014 ◽  
Vol 64 (1) ◽  
Author(s):  
S. Louboutin

AbstractWe explain how one can use the explicit formulas for the mean square values of L-functions which we established elsewhere to obtain explcit upper bounds on relative class numbers of cyclotomic number fields. As an example, we show that the relative class numbers of the cyclotomic fields of conductor 4p, p ≥ 3 a prime, are less than or equal to 8√p(p/16)(p−1)/2.


2018 ◽  
Vol 14 (10) ◽  
pp. 2631-2639 ◽  
Author(s):  
Yan Li ◽  
Xiaoyu Hu ◽  
Daeyeoul Kim

The classical Menon’s identity [P. K. Menon, On the sum [Formula: see text], J. Indian Math. Soc.[Formula: see text]N.S.[Formula: see text] 29 (1965) 155–163] states that [Formula: see text] where for a positive integer [Formula: see text], [Formula: see text] is the group of units of the ring [Formula: see text], [Formula: see text] represents the greatest common divisor, [Formula: see text] is the Euler’s totient function and [Formula: see text] is the divisor function. In this paper, we generalize Menon’s identity with Dirichlet characters in the following way: [Formula: see text] where [Formula: see text] is a non-negative integer and [Formula: see text] is a Dirichlet character modulo [Formula: see text] whose conductor is [Formula: see text]. Our result can be viewed as an extension of Zhao and Cao’s result [Another generalization of Menon’s identity, Int. J. Number Theory 13(9) (2017) 2373–2379] to [Formula: see text]. It can also be viewed as an extension of Sury’s result [Some number-theoretic identities from group actions, Rend. Circ. Mat. Palermo 58 (2009) 99–108] to Dirichlet characters.


2008 ◽  
Vol 04 (02) ◽  
pp. 249-293 ◽  
Author(s):  
NIGEL WATT

We obtain new upper bounds for the mean squared modulus of sums ∑n∈ℕAnχ(n), where the sequence (An) is fixed and the variable χ belongs to the set of non-principal Dirichlet characters for some modulus q. It is assumed that, for some M, some complex sequence (cm) satisfying cm = 0 for m ∉ (M/2,M], and some α(x) and β(y) (smooth functions with compact support), one has An = ∑uvm = n α(u)β(v)cm (n ∈ ℕ). There is a natural analogy between the bounds obtained and bounds on mean values of Dirichlet polynomials previously obtained by Deshouillers and Iwaniec. Our proofs make use of results from the spectral theory of automorphic functions, including the bound of Kim and Sarnak for the eigenvalues of Hecke operators acting on certain spaces of Maass cusp forms. The results depend on the size of P, the largest prime factor of q, and improve as log q(P) is diminished. In separate work, Harman has given an application of our results to the theory of Carmichael numbers.


1980 ◽  
Vol 23 (3) ◽  
pp. 630-645 ◽  
Author(s):  
Gerald Zimmermann ◽  
J.A. Scott Kelso ◽  
Larry Lander

High speed cinefluorography was used to track articulatory movements preceding and following full-mouth tooth extraction and alveoloplasty in two subjects. Films also were made of a control subject on two separate days. The purpose of the study was to determine the effects of dramatically altering the structural dimensions of the oral cavity on the kinematic parameters of speech. The results showed that the experimental subjects performed differently pre and postoperatively though the changes were in different directions for the two subjects. Differences in both means and variabilities of kinematic parameters were larger between days for the experimental (operated) subjects than for the control subject. The results for the Control subject also showed significant differences in the mean values of kinematic variables between days though these day-to-day differences could not account for the effects found pre- and postoperatively. The results of the kinematic analysis, particularly the finding that transition time was most stable over the experimental conditions for the operated subjects, are used to speculate about the coordination of normal speech.


1986 ◽  
Vol 55 (01) ◽  
pp. 108-111 ◽  
Author(s):  
M Köhler ◽  
P Hellstern ◽  
C Miyashita ◽  
G von Blohn ◽  
E Wenzel

SummaryThis study was performed to evaluate the influence of different routes of administration on the efficacy of DDAVP treatment. Ten healthy volunteers received DDAVP intranasally (i.n.), subcutaneously (s.c.) and intravenously (i.v.) in a randomized cross-over trial. Factor XII and high molecular weight (HMW)-kininogen levels increased only slightly after DDAVP administration. The mean increase of factor VIII: C was 3.1 (i. v.), 2.3 (s. c.), and 1.3 (i.n.) - fold over baseline. Ristocetin cofactor (von Willebrand factor antigen) increased 3.1 (2.5), 2.0 (2.3) and 1.2 (1.2) - fold over baseline mean values after i.v., s.c. and i.n. DDAVP, respectively. The half-disappearance time of factor VIII and von Willebrand factor (vWF) after DDAVP ranged from five (factor VIII: C) to eight hours (vWF). The mean increase of fibrinolytic activity was more pronounced after i.v. DDAVP. The antidiuretic effect was moderate with no apparent differences between the routes of application. This study provides further evidence that both i.v. and s.c. DDAVP administration result in an appropriate and reliable stimulation of haemostasis. An additional advantage of s. c. administration is its suitability for home treatment.


2018 ◽  
Vol 4 (4) ◽  
pp. 519-522
Author(s):  
Jeyakumar S ◽  
Jagatheesan Alagesan ◽  
T.S. Muthukumar

Background: Frozen shoulder is disorder of the connective tissue that limits the normal Range of motion of the shoulder in diabetes, frozen shoulder is thought to be caused by changes to the collagen in the shoulder joint as a result of long term Hypoglycemia. Mobilization is a therapeutic movement of the joint. The goal is to restore normal joint motion and rhythm. The use of mobilization with movement for peripheral joints was developed by mulligan. This technique combines a sustained application of manual technique “gliding” force to the joint with concurrent physiologic motion of joint, either actively or passively. This study aims to find out the effects of mobilization with movement and end range mobilization in frozen shoulder in Type I diabetics. Materials and Methods: 30 subjects both male and female, suffering with shoulder pain and clinically diagnosed with frozen shoulder was recruited for the study and divided into two groups with 15 patients each based on convenient sampling method. Group A patients received mobilization with movement and Group B patients received end range mobilization for three weeks. The outcome measurements were SPADI, Functional hand to back scale, abduction range of motion using goniometer and VAS. Results: The mean values of all parameters showed significant differences in group A as compared to group B in terms of decreased pain, increased abduction range and other outcome measures. Conclusion: Based on the results it has been concluded that treating the type 1 diabetic patient with frozen shoulder, mobilization with movement exercise shows better results than end range mobilization in reducing pain and increase functional activities and mobility in frozen shoulder.


1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.


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