We set up a series of self-consistent N -body simulations to investigate the fundamental plane of merger remnants of spiral galaxies .
These last ones are obtained from a theoretical Tully-Fisher relation at z =1 , assuming a constant mass-to-light ratio within the \Lambda CDM cosmogony .
Using a Sérsic growth curve and an orthogonal fitting method , we found that the fundamental plane of our merger remnants is described by the relation R _ { \mathrm { e } } \propto \sigma _ { 0 } ^ { 1.48 \pm 0.01 } I _ { \mathrm { e } } ^ { -0.75 \pm 0.01 } which is in good agreement with that reported from the Sloan Digital Sky Survey R _ { \mathrm { e } } \propto \sigma _ { 0 } ^ { 1.49 \pm 0.05 } I _ { \mathrm { e } } ^ { -0.75 \pm 0.01 } .
However , the R ^ { 1 / 4 } -profile leads to a fundamental plane given by R _ { \mathrm { e } } \propto \sigma _ { 0 } ^ { 1.79 \pm 0.01 } I _ { \mathrm { e } } ^ { -0.60 \pm 0.01 } .
In general , the correlation found in our merger remnants arises from homology breaking ( V ^ { 2 } \propto \sigma _ { 0 } ^ { \nu } , R _ { g } \propto R _ { \mathrm { e } } ^ { \eta } ) in combination with a mass scaling relation between the total and luminous mass , M \propto M _ { \mathrm { L } } ^ { \gamma } .
Considering an orthogonal fitting method , it is found that 1.74 \la \nu \la 1.79 , 0.21 \la \eta \la 0.52 and 0.80 \la \gamma \la 0.90 depending on the adopted profile ( Sérsic or R ^ { 1 / 4 } ) .