can it be a definition of G in a string theory ?

[stephaneww]

cf the pdf join

 

my problem is the dimension of G

 

thank you for yours answers

G.pdf

Edited December 15, 2015 by stephaneww

[imatfaal]

From PDF (which we would prefer you post in abstract on the site)

 

G is the current gravitational constant G = 6, 67384 ∗ kg ∗ m ∗ s−1

 

Well

 

F=GMm/r^2

 

 

So if we look at that in base units/dimensions you get

 

[kg][m]^-2 = G [kg]^2[m]^-2

 

divide both sides by kg^2

multiply both sides by m^2

 

and you get

[m]^3 ^-2 [kg]^-1 = G

 

you can even sub in the defintion of Newtons

 

[N] = G [kg]^2[m]^-2

 

and get

 

G = [N][kg]^-2[m]^2 which is the SI units for G

 

So no - you are incorrect. getting Newtons grav constant dimensionally wrong in a paper on gravity is not cool

[stephaneww]

ok thank you

[swansont]

!

Moderator Note

For future reference I will ONCE AGAIN remind you of the relevant part of rule 2.7: "members should be able to participate in the discussion without clicking any links or watching any videos."

 

Do not respond to this in the thread

[ajb]

Newton's constant is not fundamental in string theory, it can be calculated from the string tension and the dilaton. The only free parameter one should have in string theory is the tension.

[imatfaal]

just noticed the value of G is given incorrectly in your paper as well. It is too big by a factor of a hundred billion

[stephaneww]

just noticed the value of G is given incorrectly in your paper as well. It is too big by a factor of a hundred billion

it' noarmal in this paper i have made an error on the age of universe : its not in seconde but in billions year. it's the mistake.

 

in seconds i'ts 4,354 * 10^7

 

thank you

Edited December 16, 2015 by stephaneww