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Let N ( a , b , c , d ; n ) and t ( a , b , c , d ; n ) denote the number of representations of n as a x 2 + b y 2 + c z 2 + d w 2 and the number of representations of n as a x ( x + 1 ) 2 + b y ( y + 1 ) 2 + c z ( z + 1 ) 2 + d w ( w + 1 ) 2 , respectively, where a , b , c , d are positive integers, n is a nonnegative integer and x , y , z , w are integers. Sun established many relations between N ( a , b , c , d ; n ) and t ( a , b , c , d ; n ) and posed 23 conjectures. Yao proved five of them by using ( p , k ) -parametrization of theta functions. In this paper, we confirm four conjectures of Sun by employing theta function identities. [ABSTRACT FROM AUTHOR]

In this work we study a class of planar Hamiltonian systems perturbed with general quadratic polynomials in order to identify the number of limit cycles. Employing Melnikov functions of any order, we show that the class of systems can have at most three limit cycles and the limit is reached. [ABSTRACT FROM AUTHOR]

We study probabilistic iterated function systems (IFSs), consisting of a finite or infinite number of average-contracting bi-Lipschitz maps on R d . If our strong open set condition is also satisfied, we show that both upper and lower bounds for the Hausdorff and packing dimensions of the invariant measure can be found. Both bounds take on the familiar form of ratio of entropy to the Lyapunov exponent. Proving these bounds in this setting requires methods which are quite different from the standard methods used for average-contracting IFSs. [ABSTRACT FROM AUTHOR]

We study the growth at the golden rotation number ω = ( 5 − 1 ) / 2 of the function sequence P n ( ω ) = ∏ r = 1 n | 2 sin ⁡ π r ω | . This sequence has been variously studied elsewhere as a skew product of sines, Birkhoff sum, q-Pochhammer symbol (on the unit circle), and restricted Euler function. In particular we study the Fibonacci decimation of the sequence P n , namely the sub-sequence Q n = | ∏ r = 1 F n 2 sin ⁡ π r ω | for Fibonacci numbers F n , and prove that this renormalisation subsequence converges to a constant. From this we show rigorously that the growth of P n ( ω ) is bounded by power laws. This provides the theoretical basis to explain recent experimental results reported by Knill and Tangerman (2011) [10] . [ABSTRACT FROM AUTHOR]

Abstract: Asymptotic formulas for the positive moments of rank and crank of partitions were obtained by K. Bringmann and K. Mahlburg recently. Motivated by their works, in this paper, we prove asymptotic formulas for the -ranks and their cumulation functions. Asymptotic inequalities between these combinatorial objects are also discovered. In particular, we show that, for fixed integer and sufficiently large , and where (resp. ) denotes the number partitions of with crank (resp. rank) . [Copyright &y& Elsevier]

Abstract: We prove a particular case of the so-called “HRT conjecture”. More precisely, we show that given any planar trapezoid with vertices and given any nontrivial function f, there is no linear dependence between the time-frequency translates . Our methods are mostly number theoretical. [Copyright &y& Elsevier]

Abstract: The generalized Grötzsch function has numerous applications in geometric function theory and analytic number theory and its properties have been investigated by many authors. In this paper we study the concavity of the generalized Grötzsch function with respect to Hölder means. [Copyright &y& Elsevier]

Abstract: Analyzing several classical tests for convergence/divergence of number series, we relax the monotonicity assumption for the sequence of terms of the series. We verify the sharpness of the obtained results on corresponding classes of sequences and functions. [ABSTRACT FROM AUTHOR]