Track inductance.

If i lay two tracks paralell between the same two points, is the inductance halved compared to laying one thick track ?

I guess it may be a stripline theory calc but im not sure.

No.

If they are too close to each other, it does have some kind of influence, but not that much. If the returning (ground) current is close to one track, the current would like that one track a lot more, and the impedance would almost be the same.

A ground plane is ofcourse the best example of a low inductance connection.

Having multiple wires or tracks is sometimes used with high current and high voltage experiments. But on a circuit board is too much going on to predict what it will do.

Boardburner2: If i lay two tracks paralell between the same two points, is the inductance halved compared to laying one thick track ?

I guess it may be a stripline theory calc but im not sure.

Need to see the geometry.

With two identical striplines in parallel, but far enough apart to make their interaction negligible, then inductance behaves like resistance - yes it will be halved. This is obvious by inspection if you consider they must see the same voltage and the current will be twice as much - impedance is therefore halved.

But we're talking stripline so inductance isn't the pertinent parameter, characteristic impedance is the important thing.

Why not use a calculator to determine the correct geometry for the impedance you actually want?

This actually sounds more like microstrip than stripline.

MarkT:
The question is not whether to identical traces will have half the inductance in parallel. The question is: do the two traces in combination have less inductance than a thicker trace?

Suppose two traces of 3mm, with a gap of 3mm over 10cm. My intuition tells me that it will be almost the same inductance. When the gap would be 2cm or more, then we have something to talk about.

The inductance drops as two strips get closer since there is less magnetic field per amp overall I think. You could look up the inductance of a 2mm strip v. a 1mm strip to see...

If i lay two tracks paralell between the same two points, is the inductance halved compared to laying one thick track ?

No.