- #1

pmb

## Main Question or Discussion Point

**[SOLVED] Tensor Analysis - Request for opinion**

Seems that a few people refer to things like vectors and tensors as quantities which are invariant. For example

Dr. Bertschinger (Cosmologist at MIT) has online notes at http://arcturus.mit.edu/8.962/notes/gr1.pdf

"Introduction to Tensor Calculus for General Relativity,"

In it he writes

"Scalars and vectors are invariant under coordinate transformations;

vector components are not."

this meaning that the vector is a geometric quantity which has a coordinate independant meaning. Call this Meaning Number 1

This is an unusual use of the term "invariant" since that term usually is synonymous with scalar = tensor of rank zero. Call this Meaning Number 2

My question is this - How many go by #1 and how many go by #2 and how many dirive the meaning from context?

Thank you for your opinion.

Pete

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