307 research outputs found
Experimental fully contextual correlations
Quantum correlations are contextual yet, in general, nothing prevents the
existence of even more contextual correlations. We identify and test a
noncontextuality inequality in which the quantum violation cannot be improved
by any hypothetical postquantum theory, and use it to experimentally obtain
correlations in which the fraction of noncontextual correlations is less than
0.06. Our correlations are experimentally generated from the results of
sequential compatible tests on a four-state quantum system encoded in the
polarization and path of a single photon.Comment: REVTeX4, 6 pages, 3 figure
Intravitreal bevacizumab (Avastin) for choroidal metastasis secondary to breast carcinoma: short-term follow-up
Uveal metastases are the most common intraocular
malignancy. The most common primary sites of cancer
are from the breast (47%) and lung (21%).1
The treatment for choroidal metastasis depends on
many factors including location, multiplicity, and activity
of each tumour.1
Bevacizumab (Avastins) is a full-length humanized
murine monoclonal antibody against the VEGF molecule,
and inhibits angiogenesis and tumour growth.2
In this report, we describe the effect of a single
intravitreal injection of bevacizumab (4 mg) in a
patient with choroidal metastasis secondary to breast
cancerMedicin
Pentagrams and paradoxes
Klyachko and coworkers consider an orthogonality graph in the form of a
pentagram, and in this way derive a Kochen-Specker inequality for spin 1
systems. In some low-dimensional situations Hilbert spaces are naturally
organised, by a magical choice of basis, into SO(N) orbits. Combining these
ideas some very elegant results emerge. We give a careful discussion of the
pentagram operator, and then show how the pentagram underlies a number of other
quantum "paradoxes", such as that of Hardy.Comment: 14 pages, 4 figure
How much contextuality?
The amount of contextuality is quantified in terms of the probability of the
necessary violations of noncontextual assignments to counterfactual elements of
physical reality.Comment: 5 pages, 3 figure
Parity proofs of the Bell-Kochen-Specker theorem based on the 600-cell
The set of 60 real rays in four dimensions derived from the vertices of a
600-cell is shown to possess numerous subsets of rays and bases that provide
basis-critical parity proofs of the Bell-Kochen-Specker (BKS) theorem (a
basis-critical proof is one that fails if even a single basis is deleted from
it). The proofs vary considerably in size, with the smallest having 26 rays and
13 bases and the largest 60 rays and 41 bases. There are at least 90 basic
types of proofs, with each coming in a number of geometrically distinct
varieties. The replicas of all the proofs under the symmetries of the 600-cell
yield a total of almost a hundred million parity proofs of the BKS theorem. The
proofs are all very transparent and take no more than simple counting to
verify. A few of the proofs are exhibited, both in tabular form as well as in
the form of MMP hypergraphs that assist in their visualization. A survey of the
proofs is given, simple procedures for generating some of them are described
and their applications are discussed. It is shown that all four-dimensional
parity proofs of the BKS theorem can be turned into experimental disproofs of
noncontextuality.Comment: 19 pages, 11 tables, 3 figures. Email address of first author has
been corrected. Ref.[5] has been corrected, as has an error in Fig.3.
Formatting error in Sec.4 has been corrected and the placement of tables and
figures has been improved. A new paragraph has been added to Sec.4 and
another new paragraph to the end of the Appendi
Parity proofs of the Kochen-Specker theorem based on the 24 rays of Peres
A diagrammatic representation is given of the 24 rays of Peres that makes it
easy to pick out all the 512 parity proofs of the Kochen-Specker theorem
contained in them. The origin of this representation in the four-dimensional
geometry of the rays is pointed out.Comment: 14 pages, 6 figures and 3 tables. Three references have been added.
Minor typos have been correcte
Isomorphism between the Peres and Penrose proofs of the BKS theorem in three dimensions
It is shown that the 33 complex rays in three dimensions used by Penrose to
prove the Bell-Kochen-Specker theorem have the same orthogonality relations as
the 33 real rays of Peres, and therefore provide an isomorphic proof of the
theorem. It is further shown that the Peres and Penrose rays are just two
members of a continuous three-parameter family of unitarily inequivalent rays
that prove the theorem.Comment: 7 pages, 2 Tables. A concluding para and 9 new references have been
added to the second versio
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