Syntax for number of cores in a Sun Grid Engine job file

I want to use the HPC of my university to qsub an array job of **3** tasks. Each task runs a Matlab code which uses a solver (MOSEK) that exploits multiple **threads** to solve an optimization problem. A parameter can control the number of threads we want the solver to use. The maximum number of threads allowed should never exceed the number of cores. Suppose I want the solver to use **4 threads**. Hence, I should ensure that each task is assigned to a machine with at least 4 cores free. How can I request that in the bash file? How should I count, in turn, the memory usage (i.e., should I declare the memory per core or the total memory)? At the moment this is my bash file #$ -S /bin/bash #$ -l h_vmem=18G #$ -l tmem=18G #$ -l h_rt=480:0:0 #$ -cwd #$ -j y #Run 3 tasks #$ -t 1-3 #$ -N try date hostname #Output the Task ID echo "Task ID is $SGE_TASK_ID" matlab -nodisplay -nodesktop -nojvm -nosplash -r "main_1; ID = $SGE_TASK_ID; f_1; exit"