The aim of this paper is to study the existence of asymptotically stable solutions for a mixed functional integral equation in N variables. This is done by using a fixed point theorem of Krasnosel’skii type in the Fréchet space and the new integral inequalities with explicit estimate. In order to illustrate the results obtained here, an example is given. Mathematics subject classification (2010...

We describe a functional method to obtain the exact evolution equation of the effective action with a parameter of the bare theory. When this parameter happens to be the bare mass of the scalar field, we find a functional generalization of the Callan-Symanzik equations. Another possibility is when this parameter is the Planck constant and controls the amplitude of the fluctuations. We show the ...

In this paper, we establish the general solution of the functional equation f(nx+ y) + f(nx− y) = nf(x+ y) + nf(x− y) + 2(f(nx)− nf(x))− 2(n − 1)f(y) for fixed integers n with n 6= 0,±1 and investigate the generalized Hyers-Ulam-Rassias stability of this equation in quasi-Banach spaces.

and Applied Analysis 3 vector spaces X and Y is a solution of 1.5 if and only if there exists a unique function C : X × X × X → Y such that f x C x, x, x for all x ∈ X, and C is symmetric for each fixed one variable and is additive for fixed two variables see also 20 . The quartic functional equation 1.6 was introduced by Rassias 21 in 2000 and then in 2005 was employed by Park and Bae 22 and o...

In this paper, we obtain the general solution and the generalized Hyers-Ulam Rassias stability of the functional equation 3(f(x+ 2y) + f(x− 2y)) = 12(f(x + y) + f(x− y)) + 4f(3y)− 18f(2y) + 36f(y)− 18f(x).

A new positive definite expanded mixed finite element method is proposed for parabolic partial integrodifferential equations. Compared to expanded mixed scheme, the new expanded mixed element system is symmetric positive definite and both the gradient equation and the flux equation are separated from its scalar unknown equation. The existence and uniqueness for semidiscrete scheme are proved an...

In both boundary element methods and Trefftz-type finite element methods a partial differential equation in some domain is treated by solving a discrete problem on the boundary of the domain and possibly the boundaries between subdomains. We consider a Trefftz element formulation which is based on the complementary energy functional, and we compare different regularizations of the interelement ...

in this paper, a positive definite semi-discrete mixed finite element method was presented for two-dimensional parabolic equations. in the new positive definite systems, the gradient equation and flux equations were separated from their scalar unknown equations.  also, the existence and uniqueness of the semi-discrete mixed finite element solutions were proven. error estimates were also obtaine...

1 Department of Mathematics, School of Science, Beijing Institute of Technology, Beijing 100081, China 2 Pedagogical Department E.E., Section of Mathematics and Informatics, National and Kapodistrian University of Athens, 4, Agamemnonos Str., Aghia Paraskevi, 15342 Athens, Greece 3 School of Communication and Information Engineering, University of Electronic Science and Technology of China, Che...