Regarding Schwartz inequality and integration bounds

AI Thread Summary
The discussion centers on the application of the Cauchy-Schwarz inequality to analyze the bounds of an integral involving functions A and Z. The key question is why the lower bound of integration includes the variable "s," leading to the inequality involving "s" rather than a simpler form without it. Participants clarify that the inclusion of "s" accounts for scenarios where it can be small, affecting the upper bound while maintaining mathematical correctness. The conversation emphasizes the balance between physical intuition and mathematical rigor in the context of integration bounds. Understanding this relationship is crucial for applying Schwartz inequality effectively in such scenarios.
p4wp4w
Messages
8
Reaction score
5
Based on Schwartz inequality, I am trying to figure out why there
should/can be the "s" variable which is the lower bound of the
integration in the RHS of the following inequality:
## \left \|\int_{-s}^{0} A(t+r)Z(t+r) dr \right \|^{2} \leq s\int_{-s}^{0}\left \| A(t+r)Z(t+r) \right \|^{2} dr, ##
instead of:
## \left \|\int_{-s}^{0} A(t+r)Z(t+r) dr \right \|^{2} \leq \int_{-s}^{0}\left \| A(t+r)Z(t+r) \right \|^{2} dr. ##
 
Last edited:
Mathematics news on Phys.org
  • Like
Likes S.G. Janssens and Samy_A
p4wp4w said:
Based on Schwartz inequality, I am trying to figure out why there
should/can be the "s" variable which is the lower bound of the
integration in the RHS of the following inequality:
## \left \|\int_{-s}^{0} A(t+r)Z(t+r) dr \right \|^{2} \leq s\int_{-s}^{0}\left \| A(t+r)Z(t+r) \right \|^{2} dr, ##
instead of:
## \left \|\int_{-s}^{0} A(t+r)Z(t+r) dr \right \|^{2} \leq \int_{-s}^{0}\left \| A(t+r)Z(t+r) \right \|^{2} dr. ##
Apply the Cauchy-Schwarz inequality to the functions##f,\ g## defined by ##f(r)=A(t+r)Z(t+r)## and ##g(r)=1##.
 
  • Like
Likes p4wp4w
Samy_A said:
Apply the Cauchy-Schwarz inequality to the functions##f,\ g## defined by ##f(r)=A(t+r)Z(t+r)## and ##g(r)=1##.
Sure. My confusion was because of the example in my mind that s can be a very small value which then the upper bound will be also very small and as a result, physically conservatism but again mathematically correct. Thank you very much.
 
Suppose ,instead of the usual x,y coordinate system with an I basis vector along the x -axis and a corresponding j basis vector along the y-axis we instead have a different pair of basis vectors ,call them e and f along their respective axes. I have seen that this is an important subject in maths My question is what physical applications does such a model apply to? I am asking here because I have devoted quite a lot of time in the past to understanding convectors and the dual...
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. In Dirac’s Principles of Quantum Mechanics published in 1930 he introduced a “convenient notation” he referred to as a “delta function” which he treated as a continuum analog to the discrete Kronecker delta. The Kronecker delta is simply the indexed components of the identity operator in matrix algebra Source: https://www.physicsforums.com/insights/what-exactly-is-diracs-delta-function/ by...
Back
Top