sci.physics.relativity

"Martin Hogbin" wrote in message
news:Wp-dnV_yTLoQNSvanZ2dnUVZ8uOdnZ2d@...
>
> "Jay R. Yablon" wrote in message
> news:61mbmnF1vf2ppU1@...
>> Most of not all of the Kaluza-Klein models that I have seen employ a
>> fifth dimension which is spacelike, that is, in which the Minkowski
>> metric tensor signature is +----. These need to be compactified,
>> they
>> run into chirality issues, need for orbifolding, etc.
>>
>> I am curious if there are any reviews of theories where the extra
>> dimension is *timelike* rather than spacelike, ., with a +---+
>> signature, which of the problems that appear from an extra spacelike
>> dimension are averted, and what new perceived problems arise by
>> switching the extra dimension over from spacelike to timelike.
>>
>> In short: what are the perceived problems / challenges of Kaluza
>> Klein
>> theories that employ an extra timelike dimension, and which of the
>> problems / challenges that exist in theories with an extra spacelike
>> dimension are sidestepped or avoided?
>>
>
> I suggest posting your question on the moderated group
>
>
>
> --
> Martin Hogbin
>
Already did and got a reply. Thanks. Jay.