Wiring of No-Signaling Boxes Expands the Hypercontractivity Ribbon - - PowerPoint PPT Presentation
Wiring of No-Signaling Boxes Expands the Hypercontractivity Ribbon - - PowerPoint PPT Presentation
Wiring of No-Signaling Boxes Expands the Hypercontractivity Ribbon Salman A. Beigi Institute for Research in Fundamental Sciences (IPM) Tehran, Iran January 12, 2015 Joint work with Amin Gohari arXiv:1409.3665 Closed sets of nonlocal
Closed sets of nonlocal correlations
Closed sets of nonlocal correlations
Foundations of Physics, Vol. 24, No. 3, 1994
Q u a n t u m N
- n
l
- c
a l i t y a s a n A x i
- m
S a n d u P
- p
e s c u t a n d D a n i e l R
- h
r l i c h 2 Received July 2, 1993: revised July 19, 1993 In the conventional approach to quantum mechanics, &determinism is an axiom and nonlocality is a theorem. We consider inverting the logical order, mak#1g nonlocality an axiom and indeterminism a theorem. Nonlocal "superquantum" correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
What is the quantum principle? J. Wheeler named it the "Merlin principle" after the legendary magician who, when pursued, could change his form again and again. The more we pursue the quantum principle, the more it changes: from discreteness, to indeterminism, to sums over paths, to many worlds, and so on. By comparison, the relativity principle is easy to grasp. Relativity theory and quantum theory underlie all of physics, but we do not always know how to reconcile them. Here, we take nonlocality as the quantum principle, and we ask what nonlocality and relativistic causality together imply. It is a pleasure to dedicate this paper to Professor Fritz Rohrlich, who has contributed much to the juncture of quantum theory and relativity theory, including its most spectacular success, quantum electrodynamics, and who has written both on quantum paradoxes tll and the logical structure of physical theory, t2~ Bell t31 proved that some predictions of quantum mechanics cannot be reproduced by any theory of local physical variables. Although Bell worked within nonrelativistic quantum theory, the definition of local variable is relativistic: a local variable can be influenced only by events in its back- ward light cone, not by events outside, and can influence events in its
i U n i v e r s i t 6 L i b r e d e B r u x e l l e s , C a m p u s P l a i n e , C . P . 2 2 5 , B
- u
l e v a r d d u T r i
- m
p h e , B
- 1
5 B r u x e l l e s , B e l g i u m . 2 S c h
- l
- f
P h y s i c s a n d A s t r
- n
- m
y , T e I
- A
v i v U n i v e r s i t y , R a m a t
- A
v i v , T e l
- A
v i v 6 9 9 7 8 I s r a e l . 3 7 9 8 2 5 / 2 4 / 3
- 4
1 5
- 9
1 8 / 9 4 / 3
- 3
7 9 5 7 . / ~
- ,
1 9 9 4 P l e n u m P u b l i s h i n g C
- r
p
- r
a t i
- n
Closed sets of nonlocal correlations
Foundations of Physics, Vol. 24, No. 3, 1994
Q u a n t u m N
- n
l
- c
a l i t y a s a n A x i
- m
S a n d u P
- p
e s c u t a n d D a n i e l R
- h
r l i c h 2 Received July 2, 1993: revised July 19, 1993 In the conventional approach to quantum mechanics, &determinism is an axiom and nonlocality is a theorem. We consider inverting the logical order, mak#1g nonlocality an axiom and indeterminism a theorem. Nonlocal "superquantum" correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
What is the quantum principle? J. Wheeler named it the "Merlin principle" after the legendary magician who, when pursued, could change his form again and again. The more we pursue the quantum principle, the more it changes: from discreteness, to indeterminism, to sums over paths, to many worlds, and so on. By comparison, the relativity principle is easy to grasp. Relativity theory and quantum theory underlie all of physics, but we do not always know how to reconcile them. Here, we take nonlocality as the quantum principle, and we ask what nonlocality and relativistic causality together imply. It is a pleasure to dedicate this paper to Professor Fritz Rohrlich, who has contributed much to the juncture of quantum theory and relativity theory, including its most spectacular success, quantum electrodynamics, and who has written both on quantum paradoxes tll and the logical structure of physical theory, t2~ Bell t31 proved that some predictions of quantum mechanics cannot be reproduced by any theory of local physical variables. Although Bell worked within nonrelativistic quantum theory, the definition of local variable is relativistic: a local variable can be influenced only by events in its back- ward light cone, not by events outside, and can influence events in its
i U n i v e r s i t 6 L i b r e d e B r u x e l l e s , C a m p u s P l a i n e , C . P . 2 2 5 , B
- u
l e v a r d d u T r i
- m
p h e , B
- 1
5 B r u x e l l e s , B e l g i u m . 2 S c h
- l
- f
P h y s i c s a n d A s t r
- n
- m
y , T e I
- A
v i v U n i v e r s i t y , R a m a t
- A
v i v , T e l
- A
v i v 6 9 9 7 8 I s r a e l . 3 7 9 8 2 5 / 2 4 / 3
- 4
1 5
- 9
1 8 / 9 4 / 3
- 3
7 9 5 7 . / ~
- ,
1 9 9 4 P l e n u m P u b l i s h i n g C
- r
p
- r
a t i
- n
L i m i t
- n
N
- n
l
- c
a l i t y i n A n y W
- r
l d i n W h i c h C
- m
m u n i c a t i
- n
C
- m
p l e x i t y I s N
- t
T r i v i a l
Gilles Brassard,1 Harry Buhrman,2,3 Noah Linden,4 Andre ´ Allan Me ´thot,1 Alain Tapp,1 and Falk Unger 3
1
D e ´ p a r t e m e n t I R O , U n i v e r s i t e ´ d e M
- n
t r e ´ a l , C . P . 6 1 2 8 , S u c c u r s a l e C e n t r e
- V
i l l e , M
- n
t r e ´ a l , Q u e ´ b e c H 3 C 3 J 7 , C a n a d a
2
I L L C , U n i v e r s i t e i t v a n A m s t e r d a m , P l a n t a g e M u i d e r g r a c h t 2 4 , 1 1 8 T V A m s t e r d a m , T h e N e t h e r l a n d s
3
C e n t r u m v
- r
W i s k u n d e e n I n f
- r
m a t i c a ( C W I ) , P
- s
t O f fi c e B
- x
9 4 7 9 , 1 9 G B A m s t e r d a m , T h e N e t h e r l a n d s
4
D e p a r t m e n t
- f
M a t h e m a t i c s , U n i v e r s i t y
- f
B r i s t
- l
, U n i v e r s i t y W a l k , B r i s t
- l
, B S 8 1 T W , U n i t e d K i n g d
- m
( R e c e i v e d 2 M a r c h 2 6 ; p u b l i s h e d 2 7 J u n e 2 6 ) B e l l p r
- v
e d t h a t q u a n t u m e n t a n g l e m e n t e n a b l e s t w
- s
p a c e l i k e s e p a r a t e d p a r t i e s t
- e
x h i b i t c l a s s i c a l l y e n t h
- u
g h t h e s e c
- r
r e l a t i
- n
s a r e s t r
- n
g e r t h a n a n y t h i n g c l a s s i c a l l y a c h i e v a b l e , l i g h t ) c
- m
m u n i c a t i
- n
p
- s
s i b l e . Y e t , P
- p
e s c u i n s t a n t a n e
- u
s
PRL 96, 250401 (2006) P H Y S I C A L R E V I E W
Closed sets of nonlocal correlations
Foundations of Physics, Vol. 24, No. 3, 1994
Q u a n t u m N
- n
l
- c
a l i t y a s a n A x i
- m
S a n d u P
- p
e s c u t a n d D a n i e l R
- h
r l i c h 2 Received July 2, 1993: revised July 19, 1993 In the conventional approach to quantum mechanics, &determinism is an axiom and nonlocality is a theorem. We consider inverting the logical order, mak#1g nonlocality an axiom and indeterminism a theorem. Nonlocal "superquantum" correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
What is the quantum principle? J. Wheeler named it the "Merlin principle" after the legendary magician who, when pursued, could change his form again and again. The more we pursue the quantum principle, the more it changes: from discreteness, to indeterminism, to sums over paths, to many worlds, and so on. By comparison, the relativity principle is easy to grasp. Relativity theory and quantum theory underlie all of physics, but we do not always know how to reconcile them. Here, we take nonlocality as the quantum principle, and we ask what nonlocality and relativistic causality together imply. It is a pleasure to dedicate this paper to Professor Fritz Rohrlich, who has contributed much to the juncture of quantum theory and relativity theory, including its most spectacular success, quantum electrodynamics, and who has written both on quantum paradoxes tll and the logical structure of physical theory, t2~ Bell t31 proved that some predictions of quantum mechanics cannot be reproduced by any theory of local physical variables. Although Bell worked within nonrelativistic quantum theory, the definition of local variable is relativistic: a local variable can be influenced only by events in its back- ward light cone, not by events outside, and can influence events in its
i U n i v e r s i t 6 L i b r e d e B r u x e l l e s , C a m p u s P l a i n e , C . P . 2 2 5 , B
- u
l e v a r d d u T r i
- m
p h e , B
- 1
5 B r u x e l l e s , B e l g i u m . 2 S c h
- l
- f
P h y s i c s a n d A s t r
- n
- m
y , T e I
- A
v i v U n i v e r s i t y , R a m a t
- A
v i v , T e l
- A
v i v 6 9 9 7 8 I s r a e l . 3 7 9 8 2 5 / 2 4 / 3
- 4
1 5
- 9
1 8 / 9 4 / 3
- 3
7 9 5 7 . / ~
- ,
1 9 9 4 P l e n u m P u b l i s h i n g C
- r
p
- r
a t i
- n
L i m i t
- n
N
- n
l
- c
a l i t y i n A n y W
- r
l d i n W h i c h C
- m
m u n i c a t i
- n
C
- m
p l e x i t y I s N
- t
T r i v i a l
Gilles Brassard,1 Harry Buhrman,2,3 Noah Linden,4 Andre ´ Allan Me ´thot,1 Alain Tapp,1 and Falk Unger 3
1
D e ´ p a r t e m e n t I R O , U n i v e r s i t e ´ d e M
- n
t r e ´ a l , C . P . 6 1 2 8 , S u c c u r s a l e C e n t r e
- V
i l l e , M
- n
t r e ´ a l , Q u e ´ b e c H 3 C 3 J 7 , C a n a d a
2
I L L C , U n i v e r s i t e i t v a n A m s t e r d a m , P l a n t a g e M u i d e r g r a c h t 2 4 , 1 1 8 T V A m s t e r d a m , T h e N e t h e r l a n d s
3
C e n t r u m v
- r
W i s k u n d e e n I n f
- r
m a t i c a ( C W I ) , P
- s
t O f fi c e B
- x
9 4 7 9 , 1 9 G B A m s t e r d a m , T h e N e t h e r l a n d s
4
D e p a r t m e n t
- f
M a t h e m a t i c s , U n i v e r s i t y
- f
B r i s t
- l
, U n i v e r s i t y W a l k , B r i s t
- l
, B S 8 1 T W , U n i t e d K i n g d
- m
( R e c e i v e d 2 M a r c h 2 6 ; p u b l i s h e d 2 7 J u n e 2 6 ) B e l l p r
- v
e d t h a t q u a n t u m e n t a n g l e m e n t e n a b l e s t w
- s
p a c e l i k e s e p a r a t e d p a r t i e s t
- e
x h i b i t c l a s s i c a l l y e n t h
- u
g h t h e s e c
- r
r e l a t i
- n
s a r e s t r
- n
g e r t h a n a n y t h i n g c l a s s i c a l l y a c h i e v a b l e , l i g h t ) c
- m
m u n i c a t i
- n
p
- s
s i b l e . Y e t , P
- p
e s c u i n s t a n t a n e
- u
s
PRL 96, 250401 (2006) P H Y S I C A L R E V I E W
461, 1101-1104 (22 October 2009) | doi:10.1038/nature08400; Received 8 May 2009; Accepted 13 August 2009
I n f
- r
m a t i
- n
c a u s a l i t y a s a p h y s i c a l p r i n c i p l e
M a r c i n P a w
- w
s k i
1
, T
- m
a s z P a t e r e k
2
, D a g
- m
i r K a s z l i k
- w
s k i
2
, V a l e r i
- S
c a r a n i
2
, A n d r e a s W i n t e r
2 , 3
& M a r e k u k
- w
s k i
1 Institute of Theoretical Physics and Astrophysics, University of Gda sk, 80-952 Gda sk, Poland 1. Centre for Quantum Technologies and Department of Physics, National University of 117543 Singapore, Singapore 2. Department of Mathematics, University of B 3. Correspond
Closed sets of nonlocal correlations
Foundations of Physics, Vol. 24, No. 3, 1994
Q u a n t u m N
- n
l
- c
a l i t y a s a n A x i
- m
S a n d u P
- p
e s c u t a n d D a n i e l R
- h
r l i c h 2 Received July 2, 1993: revised July 19, 1993 In the conventional approach to quantum mechanics, &determinism is an axiom and nonlocality is a theorem. We consider inverting the logical order, mak#1g nonlocality an axiom and indeterminism a theorem. Nonlocal "superquantum" correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
What is the quantum principle? J. Wheeler named it the "Merlin principle" after the legendary magician who, when pursued, could change his form again and again. The more we pursue the quantum principle, the more it changes: from discreteness, to indeterminism, to sums over paths, to many worlds, and so on. By comparison, the relativity principle is easy to grasp. Relativity theory and quantum theory underlie all of physics, but we do not always know how to reconcile them. Here, we take nonlocality as the quantum principle, and we ask what nonlocality and relativistic causality together imply. It is a pleasure to dedicate this paper to Professor Fritz Rohrlich, who has contributed much to the juncture of quantum theory and relativity theory, including its most spectacular success, quantum electrodynamics, and who has written both on quantum paradoxes tll and the logical structure of physical theory, t2~ Bell t31 proved that some predictions of quantum mechanics cannot be reproduced by any theory of local physical variables. Although Bell worked within nonrelativistic quantum theory, the definition of local variable is relativistic: a local variable can be influenced only by events in its back- ward light cone, not by events outside, and can influence events in its
i U n i v e r s i t 6 L i b r e d e B r u x e l l e s , C a m p u s P l a i n e , C . P . 2 2 5 , B
- u
l e v a r d d u T r i
- m
p h e , B
- 1
5 B r u x e l l e s , B e l g i u m . 2 S c h
- l
- f
P h y s i c s a n d A s t r
- n
- m
y , T e I
- A
v i v U n i v e r s i t y , R a m a t
- A
v i v , T e l
- A
v i v 6 9 9 7 8 I s r a e l . 3 7 9 8 2 5 / 2 4 / 3
- 4
1 5
- 9
1 8 / 9 4 / 3
- 3
7 9 5 7 . / ~
- ,
1 9 9 4 P l e n u m P u b l i s h i n g C
- r
p
- r
a t i
- n
L i m i t
- n
N
- n
l
- c
a l i t y i n A n y W
- r
l d i n W h i c h C
- m
m u n i c a t i
- n
C
- m
p l e x i t y I s N
- t
T r i v i a l
Gilles Brassard,1 Harry Buhrman,2,3 Noah Linden,4 Andre ´ Allan Me ´thot,1 Alain Tapp,1 and Falk Unger 3
1
D e ´ p a r t e m e n t I R O , U n i v e r s i t e ´ d e M
- n
t r e ´ a l , C . P . 6 1 2 8 , S u c c u r s a l e C e n t r e
- V
i l l e , M
- n
t r e ´ a l , Q u e ´ b e c H 3 C 3 J 7 , C a n a d a
2
I L L C , U n i v e r s i t e i t v a n A m s t e r d a m , P l a n t a g e M u i d e r g r a c h t 2 4 , 1 1 8 T V A m s t e r d a m , T h e N e t h e r l a n d s
3
C e n t r u m v
- r
W i s k u n d e e n I n f
- r
m a t i c a ( C W I ) , P
- s
t O f fi c e B
- x
9 4 7 9 , 1 9 G B A m s t e r d a m , T h e N e t h e r l a n d s
4
D e p a r t m e n t
- f
M a t h e m a t i c s , U n i v e r s i t y
- f
B r i s t
- l
, U n i v e r s i t y W a l k , B r i s t
- l
, B S 8 1 T W , U n i t e d K i n g d
- m
( R e c e i v e d 2 M a r c h 2 6 ; p u b l i s h e d 2 7 J u n e 2 6 ) B e l l p r
- v
e d t h a t q u a n t u m e n t a n g l e m e n t e n a b l e s t w
- s
p a c e l i k e s e p a r a t e d p a r t i e s t
- e
x h i b i t c l a s s i c a l l y e n t h
- u
g h t h e s e c
- r
r e l a t i
- n
s a r e s t r
- n
g e r t h a n a n y t h i n g c l a s s i c a l l y a c h i e v a b l e , l i g h t ) c
- m
m u n i c a t i
- n
p
- s
s i b l e . Y e t , P
- p
e s c u i n s t a n t a n e
- u
s
PRL 96, 250401 (2006) P H Y S I C A L R E V I E W
461, 1101-1104 (22 October 2009) | doi:10.1038/nature08400; Received 8 May 2009; Accepted 13 August 2009
I n f
- r
m a t i
- n
c a u s a l i t y a s a p h y s i c a l p r i n c i p l e
M a r c i n P a w
- w
s k i
1
, T
- m
a s z P a t e r e k
2
, D a g
- m
i r K a s z l i k
- w
s k i
2
, V a l e r i
- S
c a r a n i
2
, A n d r e a s W i n t e r
2 , 3
& M a r e k u k
- w
s k i
1 Institute of Theoretical Physics and Astrophysics, University of Gda sk, 80-952 Gda sk, Poland 1. Centre for Quantum Technologies and Department of Physics, National University of 117543 Singapore, Singapore 2. Department of Mathematics, University of B 3. Correspond
A glance beyond the quantum model
BY MIGUEL NAVASCUÉS
1 , 2 ,
* AND HARALD WUNDERLICH
1 , 2 , 3 1Institute for Mathematical Sciences, Imperial College London,
S W 7 2 P G , U K
Closed sets of nonlocal correlations
Foundations of Physics, Vol. 24, No. 3, 1994
Q u a n t u m N
- n
l
- c
a l i t y a s a n A x i
- m
S a n d u P
- p
e s c u t a n d D a n i e l R
- h
r l i c h 2 Received July 2, 1993: revised July 19, 1993 In the conventional approach to quantum mechanics, &determinism is an axiom and nonlocality is a theorem. We consider inverting the logical order, mak#1g nonlocality an axiom and indeterminism a theorem. Nonlocal "superquantum" correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
What is the quantum principle? J. Wheeler named it the "Merlin principle" after the legendary magician who, when pursued, could change his form again and again. The more we pursue the quantum principle, the more it changes: from discreteness, to indeterminism, to sums over paths, to many worlds, and so on. By comparison, the relativity principle is easy to grasp. Relativity theory and quantum theory underlie all of physics, but we do not always know how to reconcile them. Here, we take nonlocality as the quantum principle, and we ask what nonlocality and relativistic causality together imply. It is a pleasure to dedicate this paper to Professor Fritz Rohrlich, who has contributed much to the juncture of quantum theory and relativity theory, including its most spectacular success, quantum electrodynamics, and who has written both on quantum paradoxes tll and the logical structure of physical theory, t2~ Bell t31 proved that some predictions of quantum mechanics cannot be reproduced by any theory of local physical variables. Although Bell worked within nonrelativistic quantum theory, the definition of local variable is relativistic: a local variable can be influenced only by events in its back- ward light cone, not by events outside, and can influence events in its
i U n i v e r s i t 6 L i b r e d e B r u x e l l e s , C a m p u s P l a i n e , C . P . 2 2 5 , B
- u
l e v a r d d u T r i
- m
p h e , B
- 1
5 B r u x e l l e s , B e l g i u m . 2 S c h
- l
- f
P h y s i c s a n d A s t r
- n
- m
y , T e I
- A
v i v U n i v e r s i t y , R a m a t
- A
v i v , T e l
- A
v i v 6 9 9 7 8 I s r a e l . 3 7 9 8 2 5 / 2 4 / 3
- 4
1 5
- 9
1 8 / 9 4 / 3
- 3
7 9 5 7 . / ~
- ,
1 9 9 4 P l e n u m P u b l i s h i n g C
- r
p
- r
a t i
- n
L i m i t
- n
N
- n
l
- c
a l i t y i n A n y W
- r
l d i n W h i c h C
- m
m u n i c a t i
- n
C
- m
p l e x i t y I s N
- t
T r i v i a l
Gilles Brassard,1 Harry Buhrman,2,3 Noah Linden,4 Andre ´ Allan Me ´thot,1 Alain Tapp,1 and Falk Unger 3
1
D e ´ p a r t e m e n t I R O , U n i v e r s i t e ´ d e M
- n
t r e ´ a l , C . P . 6 1 2 8 , S u c c u r s a l e C e n t r e
- V
i l l e , M
- n
t r e ´ a l , Q u e ´ b e c H 3 C 3 J 7 , C a n a d a
2
I L L C , U n i v e r s i t e i t v a n A m s t e r d a m , P l a n t a g e M u i d e r g r a c h t 2 4 , 1 1 8 T V A m s t e r d a m , T h e N e t h e r l a n d s
3
C e n t r u m v
- r
W i s k u n d e e n I n f
- r
m a t i c a ( C W I ) , P
- s
t O f fi c e B
- x
9 4 7 9 , 1 9 G B A m s t e r d a m , T h e N e t h e r l a n d s
4
D e p a r t m e n t
- f
M a t h e m a t i c s , U n i v e r s i t y
- f
B r i s t
- l
, U n i v e r s i t y W a l k , B r i s t
- l
, B S 8 1 T W , U n i t e d K i n g d
- m
( R e c e i v e d 2 M a r c h 2 6 ; p u b l i s h e d 2 7 J u n e 2 6 ) B e l l p r
- v
e d t h a t q u a n t u m e n t a n g l e m e n t e n a b l e s t w
- s
p a c e l i k e s e p a r a t e d p a r t i e s t
- e
x h i b i t c l a s s i c a l l y e n t h
- u
g h t h e s e c
- r
r e l a t i
- n
s a r e s t r
- n
g e r t h a n a n y t h i n g c l a s s i c a l l y a c h i e v a b l e , l i g h t ) c
- m
m u n i c a t i
- n
p
- s
s i b l e . Y e t , P
- p
e s c u i n s t a n t a n e
- u
s
PRL 96, 250401 (2006) P H Y S I C A L R E V I E W
461, 1101-1104 (22 October 2009) | doi:10.1038/nature08400; Received 8 May 2009; Accepted 13 August 2009
I n f
- r
m a t i
- n
c a u s a l i t y a s a p h y s i c a l p r i n c i p l e
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1 Institute of Theoretical Physics and Astrophysics, University of Gda sk, 80-952 Gda sk, Poland 1. Centre for Quantum Technologies and Department of Physics, National University of 117543 Singapore, Singapore 2. Department of Mathematics, University of B 3. Correspond
A glance beyond the quantum model
BY MIGUEL NAVASCUÉS
1 , 2 ,
* AND HARALD WUNDERLICH
1 , 2 , 3 1Institute for Mathematical Sciences, Imperial College London,
S W 7 2 P G , U K
2012 | Accepted 8 Jul 2013 | Published 16 Aug 2013
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- T. Fritz1,2, A.B. Sainz1, R. Augusiak1, J. Bohr Brask1, R. Chaves1,3, A. Leverrier1,4,5 & A. Acı
´n1,6
I n r e c e n t y e a r s , t h e
DOI: 10.1038/ncomms3263
Closed sets of nonlocal correlations
Foundations of Physics, Vol. 24, No. 3, 1994
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r l i c h 2 Received July 2, 1993: revised July 19, 1993 In the conventional approach to quantum mechanics, &determinism is an axiom and nonlocality is a theorem. We consider inverting the logical order, mak#1g nonlocality an axiom and indeterminism a theorem. Nonlocal "superquantum" correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
What is the quantum principle? J. Wheeler named it the "Merlin principle" after the legendary magician who, when pursued, could change his form again and again. The more we pursue the quantum principle, the more it changes: from discreteness, to indeterminism, to sums over paths, to many worlds, and so on. By comparison, the relativity principle is easy to grasp. Relativity theory and quantum theory underlie all of physics, but we do not always know how to reconcile them. Here, we take nonlocality as the quantum principle, and we ask what nonlocality and relativistic causality together imply. It is a pleasure to dedicate this paper to Professor Fritz Rohrlich, who has contributed much to the juncture of quantum theory and relativity theory, including its most spectacular success, quantum electrodynamics, and who has written both on quantum paradoxes tll and the logical structure of physical theory, t2~ Bell t31 proved that some predictions of quantum mechanics cannot be reproduced by any theory of local physical variables. Although Bell worked within nonrelativistic quantum theory, the definition of local variable is relativistic: a local variable can be influenced only by events in its back- ward light cone, not by events outside, and can influence events in its
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PRL 96, 250401 (2006) P H Y S I C A L R E V I E W
461, 1101-1104 (22 October 2009) | doi:10.1038/nature08400; Received 8 May 2009; Accepted 13 August 2009
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1 Institute of Theoretical Physics and Astrophysics, University of Gda sk, 80-952 Gda sk, Poland 1. Centre for Quantum Technologies and Department of Physics, National University of 117543 Singapore, Singapore 2. Department of Mathematics, University of B 3. Correspond
A glance beyond the quantum model
BY MIGUEL NAVASCUÉS
1 , 2 ,
* AND HARALD WUNDERLICH
1 , 2 , 3 1Institute for Mathematical Sciences, Imperial College London,
S W 7 2 P G , U K
2012 | Accepted 8 Jul 2013 | Published 16 Aug 2013
L
- c
a l
- r
t h
- g
- n
a l i t y a s a m u l t i p a r t i t e p r i n c i p l e f
- r
q u a n t u m c
- r
r e l a t i
- n
s
- T. Fritz1,2, A.B. Sainz1, R. Augusiak1, J. Bohr Brask1, R. Chaves1,3, A. Leverrier1,4,5 & A. Acı
´n1,6
I n r e c e n t y e a r s , t h e
DOI: 10.1038/ncomms3263
Closed sets of nonlocal correlations
Jonathan Allcock,1 Nicolas Brunner,2 Noah Linden,1 Sandu Popescu,2 Paul Skrzypczyk,2 and Tamás Vértesi3
1Department of Mathematics, University of Bristol, Bristol BS8 1TW, United Kingdom 2H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom 3Institute of Nuclear Research, Hungarian Academy of Sciences, P.O. Box 51, H-4001 Debrecen, Hungary
Received 11 August 2009; revised manuscript received 27 August 2009; published 11 December 2009 PHYSICAL REVIEW A 80, 062107 2009
Outline
Introduction to non-local boxes and wirings Two measures of correlation with the tensorization property
Maximal correlation Hypercontractivity ribbon
Main result: maximal correlation and hypercontractivity ribbon are monotone under wirings Example: simulation of isotropic boxes with each other
Resolves a conjecture of Lang, V´ ertesi, Navascu´ es ’14
Computability of the above invariants
Local measurements on bipartite physical systems
Local measurements on bipartite physical systems
Local measurements on bipartite physical systems
x y
Local measurements on bipartite physical systems
x y a b
Local measurements on bipartite physical systems
x y a b x a y b
Local measurements on bipartite physical systems
x y a b x a y b p(a, b|x, y) = the probability of outcomes a, b under measurement settings x, y
Local measurements on bipartite physical systems
x y a b x a y b p(a, b|x, y) = the probability of outcomes a, b under measurement settings x, y No-signaling: instantaneous signaling is impossible
p(a|xy) is independent of y p(b|xy) is independent of x
Isotropic boxes
x a y b
Example: x, y, a, b ∈ {0, 1}, and 0 ≤ η ≤ 1 PRη(a, b|x, y) :=
- 1+η
4
if a ⊕ b = xy,
1−η 4
- therwise.
Wirings
1 1 2 2
Wirings
1 1 2 2
Wirings
1 1 2 2
x0 y0 b0 a0
Wirings
1 1 2 2
x0 y0 b0 a0
Wirings are the local operations in the box world [Allcock et al. ’09] The set of physical non-local boxes is closed under wirings
Wirings
1 1 2 2
x0 y0 b0 a0
Wirings are the local operations in the box world [Allcock et al. ’09] The set of physical non-local boxes is closed under wirings Problem: 1/2 ≤ η′ < η ≤ 1. Can we generate PRη from some copies of PRη′ under wirings?
No if there are two [Short ’09] or at most nine [Forster ’11] copies of PRη′ available
Tensorization of measures of correlation
A1 B1 An Bn
A0
B0
Problem: Given some samples of pAB can we generate one sample from qA′B′ under local operations?
Tensorization of measures of correlation
A1 B1 An Bn
A0
B0
Problem: Given some samples of pAB can we generate one sample from qA′B′ under local operations? Measures of correlation are monotone under local operations I(A, B)p < I(A′, B′)q ⇒ No
Tensorization of measures of correlation
A1 B1 An Bn
A0
B0
Problem: Given some samples of pAB can we generate one sample from qA′B′ under local operations? Measures of correlation are monotone under local operations I(A, B)p < I(A′, B′)q ⇒ No NOT quite right! I(An, Bn)pn = nI(A, B)p.
Tensorization of measures of correlation
A1 B1 An Bn
A0
B0
Problem: Given some samples of pAB can we generate one sample from qA′B′ under local operations? Measures of correlation are monotone under local operations I(A, B)p < I(A′, B′)q ⇒ No NOT quite right! I(An, Bn)pn = nI(A, B)p. [Tensorization]: Is there a measure of correlation ρ such that ρ(An, Bn)pn = ρ(A, B)p?
Tensorization of measures of correlation
A1 B1 An Bn
A0
B0
Problem: Given some samples of pAB can we generate one sample from qA′B′ under local operations? Measures of correlation are monotone under local operations I(A, B)p < I(A′, B′)q ⇒ No NOT quite right! I(An, Bn)pn = nI(A, B)p. [Tensorization]: Is there a measure of correlation ρ such that ρ(An, Bn)pn = ρ(A, B)p?
Maximal correlation Hypercontractivity ribbon
Maximal correlation
Bipartite distribution pAB ρ(A, B) := max Cov(f, g)
- Var[fA]Var[gB]
fA : A → R, gB : B → R
Maximal correlation
Bipartite distribution pAB ρ(A, B) := max Cov(f, g)
- Var[fA]Var[gB]
fA : A → R, gB : B → R 0 ≤ ρ(A, B) ≤ 1, ρ(A, B) = 0 iff pAB = pA · pB
Maximal correlation
Bipartite distribution pAB ρ(A, B) := max Cov(f, g)
- Var[fA]Var[gB]
fA : A → R, gB : B → R 0 ≤ ρ(A, B) ≤ 1, ρ(A, B) = 0 iff pAB = pA · pB [Tensorization]: ρ(An, Bn) = ρ(A, B) [Data processing]: ρ(·, ·) is monotone under local operations
Maximal correlation
Bipartite distribution pAB ρ(A, B) := max Cov(f, g)
- Var[fA]Var[gB]
fA : A → R, gB : B → R 0 ≤ ρ(A, B) ≤ 1, ρ(A, B) = 0 iff pAB = pA · pB [Tensorization]: ρ(An, Bn) = ρ(A, B) [Data processing]: ρ(·, ·) is monotone under local operations Maximal correlation for non-local boxes: ρ(A, B|X, Y) := max
x,y ρ(A, B|X = x, Y = y)
Maximal correlation under wirings
x a y b
Lemma: For any no-signaling box p(ab|xy) we have ρ(A, B) ≤ max{ρ(A, B|X, Y), ρ(X, Y)}.
Maximal correlation under wirings
x a y b
Lemma: For any no-signaling box p(ab|xy) we have ρ(A, B) ≤ max{ρ(A, B|X, Y), ρ(X, Y)}. Proof:
E[fg] = EXYEAB|XY[fg] ≤EXY
- EA|XY[f] · EB|XY[g] + ρ
- VarA|XY[f] · VarB|XY[g]
- = EXY
- EA|X[f] · EB|Y[g]
- + ρEXY
- VarA|X[f] · VarB|Y[g]
- ≤EXEA|X[f] · EYEB|Y[g] + ρ
- VarXEA|X[f] · VarYEB|Y[g] + ρEXY
- VarA|X[f] · VarB|Y[g]
- ≤EXEA|X[f] · EYEB|Y[g] + ρ
- VarXEA|X[f] · VarYEB|Y[g] + ρ
- EXVarA|X[f] · EYVarB|Y[g]
≤EAX[f] · EBY[g] + ρ
- VarXEA|X[f] + EXVarA|X[f]
VarYEB|Y[g] + EYVarB|Y[g]
- =EAX[f] · EBY[g] + ρ
- VarAX[f]VarBY[g].
Maximal correlation under wirings
1 1 2 2
x0 y0 b0 a0
c
d Theorem Maximal correlation of no-signaling boxes does not increase under wirings.
Maximal correlation under wirings
1 1 2 2
x0 y0 b0 a0
Theorem Maximal correlation of no-signaling boxes does not increase under wirings. The proof doesn’t work for these types of wirings! We need new tools.
Hypercontractivity ribbon
[Ahlswede, G´ acs ’76] (λ1, λ2) ∈ R(A, B) iff E[fAgB] ≤ fA 1
λ1 gB 1 λ2 ,
∀fA, gB Schatten norm: fA 1
λ1 = E
- |fA|1/λ1λ1
Hypercontractivity ribbon
[Ahlswede, G´ acs ’76] (λ1, λ2) ∈ R(A, B) iff E[fAgB] ≤ fA 1
λ1 gB 1 λ2 ,
∀fA, gB Schatten norm: fA 1
λ1 = E
- |fA|1/λ1λ1
[Nair ’14] (λ1, λ2) ∈ R(A, B) iff: I(U; AB) ≥ λ1I(U; A) + λ2I(U; B), ∀pU|AB
Hypercontractivity ribbon
(1, 1)
[Ahlswede, G´ acs ’76] (λ1, λ2) ∈ R(A, B) iff E[fAgB] ≤ fA 1
λ1 gB 1 λ2 ,
∀fA, gB Schatten norm: fA 1
λ1 = E
- |fA|1/λ1λ1
[Nair ’14] (λ1, λ2) ∈ R(A, B) iff: I(U; AB) ≥ λ1I(U; A) + λ2I(U; B), ∀pU|AB R(A, B) = [0, 1]2 iff A, B are independent
Hypercontractivity ribbon
(1, 1)
[Ahlswede, G´ acs ’76] (λ1, λ2) ∈ R(A, B) iff E[fAgB] ≤ fA 1
λ1 gB 1 λ2 ,
∀fA, gB Schatten norm: fA 1
λ1 = E
- |fA|1/λ1λ1
[Nair ’14] (λ1, λ2) ∈ R(A, B) iff: I(U; AB) ≥ λ1I(U; A) + λ2I(U; B), ∀pU|AB R(A, B) = [0, 1]2 iff A, B are independent [Tensorization]: R(An, Bn) = R(A, B) [Data processing]: R(·, ·) expands under local operations
Hypercontractivity ribbon under wirings
Hypercontractivity ribbon for non-local boxes: R(A, B|X, Y) :=
- x,y
R(A, B|X = x, Y = y).
Hypercontractivity ribbon under wirings
Hypercontractivity ribbon for non-local boxes: R(A, B|X, Y) :=
- x,y
R(A, B|X = x, Y = y). Theorem Suppose that a no-signaling box p(a′b′|x′y′) can be generated from some copies of a box p(ab|xy) under wirings. Then R(A, B|X, Y) ⊆ R(A′, B′|X′, Y′).
Hypercontractivity ribbon under wirings
Hypercontractivity ribbon for non-local boxes: R(A, B|X, Y) :=
- x,y
R(A, B|X = x, Y = y). Theorem Suppose that a no-signaling box p(a′b′|x′y′) can be generated from some copies of a box p(ab|xy) under wirings. Then R(A, B|X, Y) ⊆ R(A′, B′|X′, Y′). Proof: Chain rule!
Example: Isotropic boxes
PRη(a, b|x, y) :=
- 1+η
4
if a ⊕ b = xy,
1−η 4
- therwise.
ρ(PRη) = η
Example: Isotropic boxes
PRη(a, b|x, y) :=
- 1+η
4
if a ⊕ b = xy,
1−η 4
- therwise.
ρ(PRη) = η Corollary For 0 ≤ η′ < η ≤ 1, using an arbitrary number of copies of PRη′, a single copy of PRη cannot be generated under wirings.
Example: Isotropic boxes
PRη(a, b|x, y) :=
- 1+η
4
if a ⊕ b = xy,
1−η 4
- therwise.
ρ(PRη) = η Corollary For 0 ≤ η′ < η ≤ 1, using an arbitrary number of copies of PRη′, a single copy of PRη cannot be generated under wirings. For 1/ √ 2 ≤ η′ < η ≤ 1, using an arbitrary number of copies of PRη′, a single copy of PRη cannot be generated under wirings with shared randomness.
Ribbon in terms of a lower convex envelope
Computation of maximal correlation is easy. How about computation of the ribbon?
Ribbon in terms of a lower convex envelope
Computation of maximal correlation is easy. How about computation of the ribbon? Define Υ(·) on the probability simplex by qAB → Υ(qAB) = λ1H(qA) + λ2H(qB) − H(qAB)
Ribbon in terms of a lower convex envelope
Computation of maximal correlation is easy. How about computation of the ribbon? Define Υ(·) on the probability simplex by qAB → Υ(qAB) = λ1H(qA) + λ2H(qB) − H(qAB) Let Υ be the lower convex envelope of Υ
distributions
Υ
e Υ
Ribbon in terms of a lower convex envelope
Computation of maximal correlation is easy. How about computation of the ribbon? Define Υ(·) on the probability simplex by qAB → Υ(qAB) = λ1H(qA) + λ2H(qB) − H(qAB) Let Υ be the lower convex envelope of Υ
distributions
Υ
e Υ
Lemma For every distribution pAB, we have (λ1, λ2) ∈ R(A, B) if and only if Υ(pAB) = Υ(pAB).
Maximal correlation ribbon
distributions
Υ
e Υ
Definition: (λ1, λ2) ∈ S(A, B) if Var[f] ≥ λ1VarAEB|A[f] + λ2VarBEA|B[f], ∀fAB
Maximal correlation ribbon
distributions
Υ
e Υ
Definition: (λ1, λ2) ∈ S(A, B) if Var[f] ≥ λ1VarAEB|A[f] + λ2VarBEA|B[f], ∀fAB R(A, B) ⊆ S(A, B)
Maximal correlation ribbon
distributions
Υ
e Υ
Definition: (λ1, λ2) ∈ S(A, B) if Var[f] ≥ λ1VarAEB|A[f] + λ2VarBEA|B[f], ∀fAB R(A, B) ⊆ S(A, B) [Tensorization]: S(An, Bn) = S(A, B) [Data processing]: S(·, ·) expands under local operations
Maximal correlation ribbon for non-local boxes
Maximal correlation ribbon for non-local boxes: S(A, B|X, Y) :=
- x,y
S(A, B|X = x, Y = y).
Maximal correlation ribbon for non-local boxes
Maximal correlation ribbon for non-local boxes: S(A, B|X, Y) :=
- x,y
S(A, B|X = x, Y = y). Theorem Suppose that a no-signaling box p(a′b′|x′y′) can be generated from some copies of box p(ab|xy) under wirings. Then S(A, B|X, Y) ⊆ S(A′, B′|X′, Y′).
Maximal correlation ribbon for non-local boxes
Maximal correlation ribbon for non-local boxes: S(A, B|X, Y) :=
- x,y
S(A, B|X = x, Y = y). Theorem Suppose that a no-signaling box p(a′b′|x′y′) can be generated from some copies of box p(ab|xy) under wirings. Then S(A, B|X, Y) ⊆ S(A′, B′|X′, Y′). Theorem ρ2(A, B) = inf
- 1−λ1
λ2
- (λ1, λ2) ∈ S(A, B)
Maximal correlation ribbon for non-local boxes
Maximal correlation ribbon for non-local boxes: S(A, B|X, Y) :=
- x,y
S(A, B|X = x, Y = y). Theorem Suppose that a no-signaling box p(a′b′|x′y′) can be generated from some copies of box p(ab|xy) under wirings. Then S(A, B|X, Y) ⊆ S(A′, B′|X′, Y′). Theorem ρ2(A, B) = inf
- 1−λ1
λ2
- (λ1, λ2) ∈ S(A, B)
- Maximal correlation is monotone under wirings