User:Sagi Harel

About myself
Sagi Harel is a graduate student in Chemical Physics in Hebrew University, Jerusalem. I'll try to contribute to Wikipedia in my area of Chemical Physics. There is a lot of jargon that it is not easy to penetrate for a newcomer - I believe Wikipedia should be a good starting point for every new field one is to discover. Also, mathematics is such a charming thing, that one can hardly stand the temptation to write about it.

"Disclaimer"
I'm fighting desperately against the errors creeping into my contributions, and I'll be grateful to everyone helping me in the battle. Also, English is not my mother tongue - so I humbly beg to correct my errors.

Contributions

 * Embedded submanifold. So far this is a stub. Needs additional information on immersion/embedding + linking to existing pages + categories
 * Scleronomous and rheonomous
 * Mathieu transformation

Wish list

 * Submanifold. Right now this points to the Glossary, but such a honorable creature definitely deserves a separate page.
 * Lanczos orthogonolization (used in time propagation).
 * Principal part in calculus: edit existing principal part page and add corresponding article in Russian.
 * Gradient: the MTW interpretation as the 1-form is beautiful - consider adding
 * Bivector, p-vector: add example in $$\mathbf{R}^3$$ vector product(pseudovector) is a dual to bivector $$\mathbf{u}\times\mathbf{v}=*(\mathbf{u}\wedge\mathbf{v})$$. Also I'm not sure that it should be defined with regard to the tangent space - exterior algebraic form is enough. Disambiguation with 3 and 4-vectors of relativity may be reworded.
 * Pseudovector - add a connection to bivectors. Also relation to dual (B&F) - visualization of antisymmetric tensor.
 * Kronecker delta - add connection to exterior products at the Generalized Kronecker symbols (SH p.754)
 * Metric tensor - add invariance of components in any coordinate system. Raising and lowering indices. Connection to Kronecker delta.
 * Push forward is defined only as differential - this is clearly incorrect. Push forward for vector field is defined only in the end of the article and the connection to the differential is therefore unclear. The simplest function push-forward is missing completely. The diagram (manifolds, objects as in AMR 4.2 may be added).
 * Mass polarization - not found.
 * Monogenic/polygenic forces

Links

 * Home page: http://www.fh.huji.ac.il/~sagi