  We study carrier interaction induced many-body effects on the excitonic
optical properties of highly photoexcited one-dimensional semiconductor quantum
wire systems by solving the dynamically screened Bethe-Salpeter equation using
realistic Coulomb interaction between carriers. Including dynamical screening
effects in the electron/hole self-energy and in the electron-hole interaction
vertex function, we find that the excitonic absorption is essentially peaked at
a constant energy for a large range of photoexcitation density ($n= 0-6\times
10^5$ cm$^{-1}$), above which the absorption peak disappears without
appreciable gain i.e., \textit{no} exciton to free electron-hole plasma Mott
transition is observed, in contrast to previous theoretical results but in
agreement with recent experimental findings. This absence of gain (or the
non-existence of a Mott transition) arises from the strong inelastic scattering
by one-dimensional plasmons or charge density excitations, closely related to
the non-Fermi liquid nature of one-dimensional systems. Our theoretical work
demonstrates a transition or a crossover in one-dimensional photoexcited
electron-hole system from an effective Fermi liquid behavior associated with a
dilute gas of noninteracting excitons in the low density region ($n<10^5$
cm$^{-1}$) to a non-Fermi liquid in the high density region ($n>10^5$
cm$^{-1}$). The conventional quasi-static approximation for this problem is
also carried out to compare with the full dynamical results. Numerical results
for exciton binding energy and absorption spectra are given as functions of
carrier density and temperature.
