scholarly journals The Bases of and the Number of Representation of Integers

2013 ◽  
Vol 2013 ◽  
pp. 1-34
Author(s):  
Barış Kendirli

Following a fundamental theorem of Hecke, some bases of and are determined, and explicit formulas are obtained for the number of representations of positive integers by all possible direct sums (111 different combinations) of seven quadratic forms from the class group of equivalence classes of quadratic forms with discriminant −71 whose representatives are .

1998 ◽  
Vol 5 (6) ◽  
pp. 545-564
Author(s):  
G. Lomadze

Abstract A way of finding exact explicit formulas for the number of representations of positive integers by quadratic forms in 12 variables with integral coefficients is suggested.


2000 ◽  
Vol 7 (2) ◽  
pp. 355-372
Author(s):  
G. Lomadze

Abstract A sum of the singular series corresponding to the number of representations of positive integers by some diagonal quadratic forms with integral coefficients is obtained.


2007 ◽  
Vol 03 (03) ◽  
pp. 475-501 ◽  
Author(s):  
THOMAS A. SCHMIDT ◽  
MARK SHEINGORN

The Markoff spectrum of binary indefinite quadratic forms can be studied in terms of heights of geodesics on low-index covers of the modular surface. The lowest geodesics on [Formula: see text] are the simple closed geodesics; these are indexed up to isometry by Markoff triples of positive integers (x, y, z) with x2 + y2 + z2 = 3xyz, and have heights [Formula: see text]. Geodesics considered by Crisp and Moran have heights [Formula: see text]; they conjectured that these heights, which lie in the "mysterious region" between 3 and the Hall ray, are isolated in the Markoff Spectrum. In our previous work, we classified the low height-achieving non-simple geodesics of [Formula: see text] into seven types according to the topology of highest arcs. Here, we obtain explicit formulas for the heights of geodesics of the first three types; the conjecture holds for approximation by closed geodesics of any of these types. Explicit examples show that each of the remaining types is realized.


1997 ◽  
Vol 4 (6) ◽  
pp. 523-532
Author(s):  
G. Lomadze

Abstract Explicit exact formulas are obtained for the number of representations of positive integers by some direct sums of quadratic forms and .


2001 ◽  
Vol 8 (1) ◽  
pp. 87-95
Author(s):  
N. Kachakhidze

Abstract The systems of bases are constructed for the spaces of cusp forms S 2m (Γ0(5), χ m ) and S 2m (Γ0(13), χ m ) for an arbitrary integer m ≥ 2. Formulas are obtained for the number of representations of a positive integers by the direct sums of some quaternary quadratic forms.


1996 ◽  
Vol 3 (5) ◽  
pp. 485-500
Author(s):  
G. Lomadze

Abstract Entire modular forms of weights and for the congruence group Γ0(4N) are constructed, which will be useful for revealing the arithmetical sense of additional terms in formulas for the number of representations of positive integers by quadratic forms in 7 and 9 variables.


2015 ◽  
Vol 58 (4) ◽  
pp. 858-868 ◽  
Author(s):  
Kenneth S. Williams

AbstractLet denote the Dedekind eta function. We use a recent productto- sum formula in conjunction with conditions for the non-representability of integers by certain ternary quadratic forms to give explicitly ten eta quotientssuch that the Fourier coefficients c(n) vanish for all positive integers n in each of infinitely many non-overlapping arithmetic progressions. For example, we show that if we have c(n) = 0 for all n in each of the arithmetic progressions


2020 ◽  
Vol 12 ◽  
Author(s):  
Bellaouar Djamel ◽  
Boudaoud Abdelmadjid

In \cite{A.Boudaoud1}, the author asked the following question: Which $n\in \mathbb{N}$ unlimited can be represented as a sum $% n=s+w_{1}w_{2}$, where $s\in \mathbb{Z}$ is a limited integer and $\omega _{1}$, $\omega _{2}$ are two unlimited positive integers? In this survey article we partially answer this question, i.e., we present some families of unlimited positive integers which can be written as the sum of a limited integer and the product of at least two unlimited positive integers.


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