We performed geometric pulsar light curve modeling using static , retarded vacuum , and offset polar cap ( PC ) dipole B -fields ( the latter is characterized by a parameter \epsilon ) , in conjunction with standard two-pole caustic ( TPC ) and outer gap ( OG ) emission geometries .
The offset-PC dipole B -field mimics deviations from the static dipole ( which corresponds to \epsilon = 0 ) .
In addition to constant-emissivity geometric models , we also considered a slot gap ( SG ) E -field associated with the offset-PC dipole B -field and found that its inclusion leads to qualitatively different light curves .
Solving the particle transport equation shows that the particle energy only becomes large enough to yield significant curvature radiation at large altitudes above the stellar surface , given this relatively low E -field .
Therefore , particles do not always attain the radiation-reaction limit .
Our overall optimal light curve fit is for the retarded vacuum dipole field and OG model , at an inclination angle \alpha = 78 { { } _ { -1 } ^ { +1 } } ^ { \circ } and observer angle \zeta = 69 { { } _ { -1 } ^ { +2 } } ^ { \circ } .
For this B -field , the TPC model is statistically disfavored compared to the OG model .
For the static dipole field , neither model is significantly preferred .
We found that smaller values of \epsilon are favored for the offset-PC dipole field when assuming constant emissivity , and larger \epsilon values favored for variable emissivity , but not significantly so .
When multiplying the SG E -field by a factor of 100 , we found improved light curve fits , with \alpha and \zeta being closer to best fits from independent studies , as well as curvature radiation reaction at lower altitudes .