How to express curvature of a level set in terms of derivatives of a function?












2












$begingroup$


Suppose I have a smooth function $u:mathbb R^ntomathbb R$.
Assume that its gradient doesn't vanish (near any point where we investigate it).
Is there a list of different (intrinsic and extrinsic) curvature quantities of level sets of $u$ in terms of derivatives of $u$?
I have been unable to find such a list.



The level set is a Riemannian manifold and its curvature can be described by various curvature tensors.
It is also a submanifold of the ambient $mathbb R^n$ and the second fundamental form describes its curvature as a submanifold.
These are what I refer to as intrinsic and extrinsic curvature quantities.



Here are two examples of questions that the list should answer.
I am looking for a resource that would contain the answer to these two questions and many others, not just the answer to these two. These example questions give a criterion for what I am looking for, that's all. This question is a reference request.




  • If $n=3$, what is the Gaussian curvature of $u^{-1}(u(0))$ at $0$ in terms of derivatives of $u$?

  • How to express the mean curvature of the level set in terms of derivatives of $u$ in any dimension?










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  • $begingroup$
    Have you looked through do Carmo?
    $endgroup$
    – Neal
    Jul 16 '15 at 11:18










  • $begingroup$
    @Neal, I haven't. Based on a quick glance it seems like a probable source, so I will take a look. Thanks for the tip!
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:34
















2












$begingroup$


Suppose I have a smooth function $u:mathbb R^ntomathbb R$.
Assume that its gradient doesn't vanish (near any point where we investigate it).
Is there a list of different (intrinsic and extrinsic) curvature quantities of level sets of $u$ in terms of derivatives of $u$?
I have been unable to find such a list.



The level set is a Riemannian manifold and its curvature can be described by various curvature tensors.
It is also a submanifold of the ambient $mathbb R^n$ and the second fundamental form describes its curvature as a submanifold.
These are what I refer to as intrinsic and extrinsic curvature quantities.



Here are two examples of questions that the list should answer.
I am looking for a resource that would contain the answer to these two questions and many others, not just the answer to these two. These example questions give a criterion for what I am looking for, that's all. This question is a reference request.




  • If $n=3$, what is the Gaussian curvature of $u^{-1}(u(0))$ at $0$ in terms of derivatives of $u$?

  • How to express the mean curvature of the level set in terms of derivatives of $u$ in any dimension?










share|cite|improve this question









$endgroup$












  • $begingroup$
    Have you looked through do Carmo?
    $endgroup$
    – Neal
    Jul 16 '15 at 11:18










  • $begingroup$
    @Neal, I haven't. Based on a quick glance it seems like a probable source, so I will take a look. Thanks for the tip!
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:34














2












2








2


1



$begingroup$


Suppose I have a smooth function $u:mathbb R^ntomathbb R$.
Assume that its gradient doesn't vanish (near any point where we investigate it).
Is there a list of different (intrinsic and extrinsic) curvature quantities of level sets of $u$ in terms of derivatives of $u$?
I have been unable to find such a list.



The level set is a Riemannian manifold and its curvature can be described by various curvature tensors.
It is also a submanifold of the ambient $mathbb R^n$ and the second fundamental form describes its curvature as a submanifold.
These are what I refer to as intrinsic and extrinsic curvature quantities.



Here are two examples of questions that the list should answer.
I am looking for a resource that would contain the answer to these two questions and many others, not just the answer to these two. These example questions give a criterion for what I am looking for, that's all. This question is a reference request.




  • If $n=3$, what is the Gaussian curvature of $u^{-1}(u(0))$ at $0$ in terms of derivatives of $u$?

  • How to express the mean curvature of the level set in terms of derivatives of $u$ in any dimension?










share|cite|improve this question









$endgroup$




Suppose I have a smooth function $u:mathbb R^ntomathbb R$.
Assume that its gradient doesn't vanish (near any point where we investigate it).
Is there a list of different (intrinsic and extrinsic) curvature quantities of level sets of $u$ in terms of derivatives of $u$?
I have been unable to find such a list.



The level set is a Riemannian manifold and its curvature can be described by various curvature tensors.
It is also a submanifold of the ambient $mathbb R^n$ and the second fundamental form describes its curvature as a submanifold.
These are what I refer to as intrinsic and extrinsic curvature quantities.



Here are two examples of questions that the list should answer.
I am looking for a resource that would contain the answer to these two questions and many others, not just the answer to these two. These example questions give a criterion for what I am looking for, that's all. This question is a reference request.




  • If $n=3$, what is the Gaussian curvature of $u^{-1}(u(0))$ at $0$ in terms of derivatives of $u$?

  • How to express the mean curvature of the level set in terms of derivatives of $u$ in any dimension?







multivariable-calculus differential-geometry reference-request riemannian-geometry curvature






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share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jul 16 '15 at 11:03









Joonas IlmavirtaJoonas Ilmavirta

20.7k94282




20.7k94282












  • $begingroup$
    Have you looked through do Carmo?
    $endgroup$
    – Neal
    Jul 16 '15 at 11:18










  • $begingroup$
    @Neal, I haven't. Based on a quick glance it seems like a probable source, so I will take a look. Thanks for the tip!
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:34


















  • $begingroup$
    Have you looked through do Carmo?
    $endgroup$
    – Neal
    Jul 16 '15 at 11:18










  • $begingroup$
    @Neal, I haven't. Based on a quick glance it seems like a probable source, so I will take a look. Thanks for the tip!
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:34
















$begingroup$
Have you looked through do Carmo?
$endgroup$
– Neal
Jul 16 '15 at 11:18




$begingroup$
Have you looked through do Carmo?
$endgroup$
– Neal
Jul 16 '15 at 11:18












$begingroup$
@Neal, I haven't. Based on a quick glance it seems like a probable source, so I will take a look. Thanks for the tip!
$endgroup$
– Joonas Ilmavirta
Jul 16 '15 at 12:34




$begingroup$
@Neal, I haven't. Based on a quick glance it seems like a probable source, so I will take a look. Thanks for the tip!
$endgroup$
– Joonas Ilmavirta
Jul 16 '15 at 12:34










1 Answer
1






active

oldest

votes


















2












$begingroup$

For the first, you might want to look at a tech report I wrote several years back:



http://cs.brown.edu/people/jhughes/papers/Hughes-DGO-2003/paper.pdf



For the second, there's a quite general paper (of which why tech report is a distillation in the 3D case, with a correction):



Peter Dombrowski. Krümmungsgrößen gleichungsdefinierter untermannigfaltigkeiten riemmannscher mannigfaltigkeiten. Mathematische Nachrichten, 38(3/4):133–180, 1968.








share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:26










  • $begingroup$
    @John Hughes, the link you posted is broken nowadays.
    $endgroup$
    – stewori
    Jan 11 at 16:34






  • 1




    $begingroup$
    Fixed! (They changed my username a few months back, darn it!)
    $endgroup$
    – John Hughes
    Jan 11 at 17:04











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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









2












$begingroup$

For the first, you might want to look at a tech report I wrote several years back:



http://cs.brown.edu/people/jhughes/papers/Hughes-DGO-2003/paper.pdf



For the second, there's a quite general paper (of which why tech report is a distillation in the 3D case, with a correction):



Peter Dombrowski. Krümmungsgrößen gleichungsdefinierter untermannigfaltigkeiten riemmannscher mannigfaltigkeiten. Mathematische Nachrichten, 38(3/4):133–180, 1968.








share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:26










  • $begingroup$
    @John Hughes, the link you posted is broken nowadays.
    $endgroup$
    – stewori
    Jan 11 at 16:34






  • 1




    $begingroup$
    Fixed! (They changed my username a few months back, darn it!)
    $endgroup$
    – John Hughes
    Jan 11 at 17:04
















2












$begingroup$

For the first, you might want to look at a tech report I wrote several years back:



http://cs.brown.edu/people/jhughes/papers/Hughes-DGO-2003/paper.pdf



For the second, there's a quite general paper (of which why tech report is a distillation in the 3D case, with a correction):



Peter Dombrowski. Krümmungsgrößen gleichungsdefinierter untermannigfaltigkeiten riemmannscher mannigfaltigkeiten. Mathematische Nachrichten, 38(3/4):133–180, 1968.








share|cite|improve this answer











$endgroup$













  • $begingroup$
    Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:26










  • $begingroup$
    @John Hughes, the link you posted is broken nowadays.
    $endgroup$
    – stewori
    Jan 11 at 16:34






  • 1




    $begingroup$
    Fixed! (They changed my username a few months back, darn it!)
    $endgroup$
    – John Hughes
    Jan 11 at 17:04














2












2








2





$begingroup$

For the first, you might want to look at a tech report I wrote several years back:



http://cs.brown.edu/people/jhughes/papers/Hughes-DGO-2003/paper.pdf



For the second, there's a quite general paper (of which why tech report is a distillation in the 3D case, with a correction):



Peter Dombrowski. Krümmungsgrößen gleichungsdefinierter untermannigfaltigkeiten riemmannscher mannigfaltigkeiten. Mathematische Nachrichten, 38(3/4):133–180, 1968.








share|cite|improve this answer











$endgroup$



For the first, you might want to look at a tech report I wrote several years back:



http://cs.brown.edu/people/jhughes/papers/Hughes-DGO-2003/paper.pdf



For the second, there's a quite general paper (of which why tech report is a distillation in the 3D case, with a correction):



Peter Dombrowski. Krümmungsgrößen gleichungsdefinierter untermannigfaltigkeiten riemmannscher mannigfaltigkeiten. Mathematische Nachrichten, 38(3/4):133–180, 1968.









share|cite|improve this answer














share|cite|improve this answer



share|cite|improve this answer








edited Jan 11 at 17:04

























answered Jul 16 '15 at 12:17









John HughesJohn Hughes

63.9k24191




63.9k24191












  • $begingroup$
    Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:26










  • $begingroup$
    @John Hughes, the link you posted is broken nowadays.
    $endgroup$
    – stewori
    Jan 11 at 16:34






  • 1




    $begingroup$
    Fixed! (They changed my username a few months back, darn it!)
    $endgroup$
    – John Hughes
    Jan 11 at 17:04


















  • $begingroup$
    Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
    $endgroup$
    – Joonas Ilmavirta
    Jul 16 '15 at 12:26










  • $begingroup$
    @John Hughes, the link you posted is broken nowadays.
    $endgroup$
    – stewori
    Jan 11 at 16:34






  • 1




    $begingroup$
    Fixed! (They changed my username a few months back, darn it!)
    $endgroup$
    – John Hughes
    Jan 11 at 17:04
















$begingroup$
Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
$endgroup$
– Joonas Ilmavirta
Jul 16 '15 at 12:26




$begingroup$
Thanks! I will take a look at the report when I have the time. I actually already knew the answer to the second question (the 1-Laplacian of $u$), but I included it as an example because it is in the spirit of things that I would like to see. (I tried to improve the formatting of the German title. I hope I got it right.)
$endgroup$
– Joonas Ilmavirta
Jul 16 '15 at 12:26












$begingroup$
@John Hughes, the link you posted is broken nowadays.
$endgroup$
– stewori
Jan 11 at 16:34




$begingroup$
@John Hughes, the link you posted is broken nowadays.
$endgroup$
– stewori
Jan 11 at 16:34




1




1




$begingroup$
Fixed! (They changed my username a few months back, darn it!)
$endgroup$
– John Hughes
Jan 11 at 17:04




$begingroup$
Fixed! (They changed my username a few months back, darn it!)
$endgroup$
– John Hughes
Jan 11 at 17:04


















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