Bifurcations of periodic solutions of delay differential equations (Q1874337)

The author extends the method of \textit{J. L. Kaplan} and \textit{J. A. Yorke} [J. Differ. Equations 23, 293-314 (1977; Zbl 0307.34070)] to prove the existence of periodic solutions with certain period in scalar delay differential equations of the type \(\dot x(t)= F(x(t), x(t-r), x(t-2r))\), where \(F\) satisfies the relation \(F(x,y,-x)=-F(-x,-y,x)\). For \(F\) depending on parameters, the paper gives conditions under which Hopf and saddle-node bifurcations of periodic solutions occur. Moreover, the author provides examples showing that Hopf and saddle-node bifurcations often occur infinitely many times.