Andrew Jordan (AJ) University of Rochester

mentions negative pressure from Phys Rev editors re: retro-casual interpretation

Tollaksen is here BTW but Nauenberg did not make it - too bad.

Menas Kafatos also here

ABL 1964 both past and future boundary condition of pre & post-selection - time symmetric

weak value have both pre and post selection constraints.

See my Journal of Cosmology Vol 14 April 2011 paper for the math - free online (edited by Penrose and Hameroff)

weak value WV can exceed eigenvalue range (i.e. negative probabilities weighting the eigenvalues) and need not not be real number, can be a complex number

Stern-Gerlach test of WV actually carried out at University of Rochester with DARPA & NSF funding.

pre-selection

weak splitting in z

strong splitting in x

post-selection in x

record the z-delection

<history|A|destiny>/<history|destiny> = <A>weak

If <history|destiny> ---> 0 you exceed eigenvalue range but with small probability

weak measurement experiments in solid state quantum hall effect relevant to quantum computers

also optical systems

Optical telecom for super internet can use weak measurements with value added.

There is technological spin-off not just idle theory. Obama gave Yakir Aharonov a medal for this work.

Spin Hall Effect of Light via Weak Measurements - spintronics

Weak measurement technology/protocol way of measuring tiny signals in large noise fields.

Ultrasensitive beam deflection measurement via interferometric weak value amplification.

Nature 463 Feb 2010 Aephraim Steinberg "Light Touch"

Sagnac effect weak measurement - which path photon took CW or CCW on rotating interferometer?

this can measure very small shifts in optical parameters using both pre and post-selection technique.

560 femto-radian deflection signal i.e width of human hair on Moon can be seen from Earth

So for GPS Drones in Pakistan and Afghanistan - amazing resolution for military operations against terrorists for example.

Also for seeing exo-planets in 100 year Star Ship Study (NASA/DARPA)

Weak value precision phase measurements! For Kip Thorne's gravity LISA/LIGO detectors of big bang inflation physics.

pico-radian measurements with only few hours of integration time.

They have a patent!

Measurement Contextual Values (MCV aka POVM) - new interpretation of QM. PRL 104, 240401 (2010) avoids negative probabilities - more palatable for orthodox thinkers

get averages of operator moments, also find conditioned averages

include post-selection and any measurement interaction strength

weak measurement is a practical tool for precision measurements in optical, solid state et-al systems