## Search

Now showing items 1-10 of 11

#### On constant-sign periodic solutions in modelling the spread of interdependent epidemics

(Cambridge University Press (CUP), 2006-01-01)

We consider the following model that describes the spread of n types of epidemics which are interdependent on each other:
u(i)(t) = integral(t)(t-r) g(i)(t, s) f(i) (s, u(1)(s), u(2)(s),..., u(n)(s))ds, t is an element of ...

#### Construction of upper and lower solutions for singular discrete initial and boundary value problems via inequality theory

(Springer Nature, 2005-01-01)

We present new existence results for singular discrete initial and boundary value problems. In particular our nonlinearity may be singular in its dependent variable and is allowed to change sign.

#### Solvability of singular second order m-point boundary value problems

(Elsevier BV, 2005-01-01)

#### Twin positive periodic solutions of second order singular differential systems

(Uniwersytet Mikolaja Kopernika/Nicolaus Copernicus University, 2005-06-01)

In this paper, we study positive periodic solutions to singular second order differential systems. It is proved that such a problem has at least two positive periodic solutions. The proof relies on a nonlinear alternative ...

#### Multiplicity of positive periodic solutions to second order differential equations

(Cambridge University Press (CUP), 2006-04-01)

In this paper, we study the existence of positive periodic solutions to the equation x" = f (t, x). It is proved that such a equation has more than one positive periodic solution when the nonlinearity changes sign. ...

#### Dynamic equations on time scales: a survey

(Elsevier BV, 2002-04-01)

#### Fixed point theory for self maps between fréchet spaces

(Elsevier BV, 2001-04-01)

#### Unbounded positive solutions for second order singular boundary value problems with derivative dependence on infinite intervals

(Division of Functional Equations, The Mathematical Society of Japan (JST), 2008-01-01)

The existence of at least one unbounded positive solution and the existence of multiple unbounded positive solutions are established for the singular second-order boundary value problem p(t)(-1)(p(t)x'(t))' + Phi(t)f(t,x,px') ...

#### Existence and quasilinearization in banach spaces

(Elsevier BV, 2009-10-01)