A bstract In recent years, several pulsar timing array collaborations have reported first hints
for a stochastic gravitational wave background at nano-Hertz frequencies. Here we …

In this work, we construct promising model-building routes towards SO (10) grand unified
theory inflation and examine their ability to explain the recent pulsar timing arrays (PTAs) …

Composite topological structures such as superheavy “quasistable strings”(QSS) and “walls
bounded by strings”(WBS) arise in realistic extensions of the Standard Model of high energy …

Many symmetry breaking patterns in grand unified theories (GUTs) give rise to cosmic
strings that eventually decay when pairs of GUT monopoles spontaneously nucleate along …

A series of pulsar timing arrays (PTAs) recently observed gravitational waves at the
nanohertz frequencies. Motivated by this remarkable result, we present a novel class of Pati …

Motivated by the NANOGrav 15 year data and other recent investigations of stochastic
gravitational background radiation based on pulsar timing arrays, we show how superheavy …

We show that, when connected with monopoles, the flat D-flat direction breaking the local U
(1) BL symmetry as an extension of the minimal supersymmetric standard model can be …

A bstract We explore a variety of composite topological structures that arise from the
spontaneous breaking of SO (10) to SU (3) c× U (1) em via one of its maximal subgroups SU …

We discuss the formation of cosmic strings or macroscopic color flux tubes at the phase
transition from the deconfinement to confinement phase in pure Yang–Mills (YM) theory …

We discuss how in SO (10) grand unification an observable number density of topologically
stable intermediate mass (∼ 10 14 GeV) monopoles survive inflation driven by a Coleman …