  Recent times have seen surge of research activity on systems combining fluid
mechanics and electromagnetic fields. In radiation optics, whenever information
about the distribution of pressure in a dielectric fluid is required, the
contribution from electrostriction becomes important. In the present paper we
calculate how the local pressure varies with position and time when a laser
beam is imposed in a uniform fluid. A Gaussian intensity profile of arbitrary
time dependence is assumed for the beam, and general results are derived in
this case. For demonstration we analyze two different cases: first, that the
beam is imposed suddenly (mathematically in the form of a step function);
secondly, that the beam is switched on in a soft way. In both cases, simple
analytical expressions for the pressure distribution are found.
