Is normalizing automorphism in $mathbbR^n$ by Jacobian still an automorphism?

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Let $n in mathbbN$.
Suppose $f: mathbbR^n to mathbbR^n$ is a $C^infty$ diffeomorphism. Let $J_f: mathbbR^n to textM (n, mathbbR)$ be the Jacobian of $f$. Is the map $F: mathbbR^n to mathbbR^n$ defined by $F(x) = [J_f(x)]^-1cdot f(x)$ a $C^infty$ diffeomorphism?







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    up vote
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    Let $n in mathbbN$.
    Suppose $f: mathbbR^n to mathbbR^n$ is a $C^infty$ diffeomorphism. Let $J_f: mathbbR^n to textM (n, mathbbR)$ be the Jacobian of $f$. Is the map $F: mathbbR^n to mathbbR^n$ defined by $F(x) = [J_f(x)]^-1cdot f(x)$ a $C^infty$ diffeomorphism?







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      up vote
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      Let $n in mathbbN$.
      Suppose $f: mathbbR^n to mathbbR^n$ is a $C^infty$ diffeomorphism. Let $J_f: mathbbR^n to textM (n, mathbbR)$ be the Jacobian of $f$. Is the map $F: mathbbR^n to mathbbR^n$ defined by $F(x) = [J_f(x)]^-1cdot f(x)$ a $C^infty$ diffeomorphism?







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      Let $n in mathbbN$.
      Suppose $f: mathbbR^n to mathbbR^n$ is a $C^infty$ diffeomorphism. Let $J_f: mathbbR^n to textM (n, mathbbR)$ be the Jacobian of $f$. Is the map $F: mathbbR^n to mathbbR^n$ defined by $F(x) = [J_f(x)]^-1cdot f(x)$ a $C^infty$ diffeomorphism?









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      edited 2 days ago









      Alfred Yerger

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      asked Aug 3 at 22:29









      Better2BLucky

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          I don't think this is even true for $mathbbR$.



          Consider the function $x^3 + e^x$. This function is clearly smooth and bijective, and the inverse is smooth by repeated application of the inverse function theorem, as the derivative has no zeros, and the inverse function theorem can be iterated to arbitrarily many derivatives.



          However, for us here, the Jacobian is just the derivative, and your map $F$ is just $f/f'$. But for us, this is $fracx^3 + e^x3x^2 + e^x$ which is not injective. In particular, it attains the value $1$ at $0$, but also at $x = 3$






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            1 Answer
            1






            active

            oldest

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            1 Answer
            1






            active

            oldest

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            active

            oldest

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            active

            oldest

            votes








            up vote
            7
            down vote



            accepted










            I don't think this is even true for $mathbbR$.



            Consider the function $x^3 + e^x$. This function is clearly smooth and bijective, and the inverse is smooth by repeated application of the inverse function theorem, as the derivative has no zeros, and the inverse function theorem can be iterated to arbitrarily many derivatives.



            However, for us here, the Jacobian is just the derivative, and your map $F$ is just $f/f'$. But for us, this is $fracx^3 + e^x3x^2 + e^x$ which is not injective. In particular, it attains the value $1$ at $0$, but also at $x = 3$






            share|cite|improve this answer



























              up vote
              7
              down vote



              accepted










              I don't think this is even true for $mathbbR$.



              Consider the function $x^3 + e^x$. This function is clearly smooth and bijective, and the inverse is smooth by repeated application of the inverse function theorem, as the derivative has no zeros, and the inverse function theorem can be iterated to arbitrarily many derivatives.



              However, for us here, the Jacobian is just the derivative, and your map $F$ is just $f/f'$. But for us, this is $fracx^3 + e^x3x^2 + e^x$ which is not injective. In particular, it attains the value $1$ at $0$, but also at $x = 3$






              share|cite|improve this answer

























                up vote
                7
                down vote



                accepted







                up vote
                7
                down vote



                accepted






                I don't think this is even true for $mathbbR$.



                Consider the function $x^3 + e^x$. This function is clearly smooth and bijective, and the inverse is smooth by repeated application of the inverse function theorem, as the derivative has no zeros, and the inverse function theorem can be iterated to arbitrarily many derivatives.



                However, for us here, the Jacobian is just the derivative, and your map $F$ is just $f/f'$. But for us, this is $fracx^3 + e^x3x^2 + e^x$ which is not injective. In particular, it attains the value $1$ at $0$, but also at $x = 3$






                share|cite|improve this answer















                I don't think this is even true for $mathbbR$.



                Consider the function $x^3 + e^x$. This function is clearly smooth and bijective, and the inverse is smooth by repeated application of the inverse function theorem, as the derivative has no zeros, and the inverse function theorem can be iterated to arbitrarily many derivatives.



                However, for us here, the Jacobian is just the derivative, and your map $F$ is just $f/f'$. But for us, this is $fracx^3 + e^x3x^2 + e^x$ which is not injective. In particular, it attains the value $1$ at $0$, but also at $x = 3$







                share|cite|improve this answer















                share|cite|improve this answer



                share|cite|improve this answer








                edited Aug 4 at 3:11


























                answered Aug 4 at 3:04









                Alfred Yerger

                9,2761743




                9,2761743






















                     

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