I want to discuss here a very unusual idea that many "serious" theoretical physicists don't want to discuss, but I think it is time for such a discussion, because many things in mathematics for physics have changed in the last 10 years.(adsbygoogle = window.adsbygoogle || []).push({});

When we calculate in chiral scalar superfields then we get e.g. ghost fields and tachyonic properties. When we calculate in AdS in 5 Dimensions, then we get some typical hyperbolic paradox. When we work in Kaluza-Klein Modells, then we find some irritating things, which we cannot solve.

And all is in my view from my research kind of time problem. (temperature or entropy problem you can say)

In the past we always said, that additional time dimensions are not possible because of the cauchy problem of partial differential equation in the type of

with q>1. q is the time dimension.

They are called ultra hyperbolic differential equation. It was studied by Cauchy and others in the 1930s and was a theoretical idea for a global solution but never really taken seriously and many problems are combined with this solution.

If we have a Model with 2 or 3 time dimensions, then we have

1. a causality problem. Violation of causality through time like loops.

2. Violation of unitarity

3. Existance of tachyonic modes

4. Presence of ghostfields

But now, we have similar problems without these additional time dimensions also. We can produce time like loops with Kerr Newmann Metric, we have all other problems with chiral scalar superfields too.

There is since 2008 a new kind of thinking how to solve the problem. Craig and Weinstein solved the Cauchy problem of ultra hyperbolic differential equations.

http://arxiv.org/pdf/0812.3869v1.pdf

They gave a non local condition for the existance of a global solution. It is working for q=2 and working for linear ultra hyperbolic partial differential equations.

Following to this thinking there are now some other researcher who are working with spacelike additional time dimensions.

What do you know about such new ideas and what do you think of it?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# A Spacelike additional time dimensions

**Physics Forums | Science Articles, Homework Help, Discussion**