200,991 research outputs found
On the geometric order of totally nondegenerate CR manifolds
No full textA CR manifold M, with CR distribution D10⊂ TCM, is called totally nondegenerate of depthμ if: (a) the complex tangent space TCM is generated by all complex vector fields that might be determined by iterated Lie brackets between at most μ fields in D10+ D10 ̄ ; (b) for each integer 2 ≤ k≤ μ- 1 , the families of all vector fields that might be determined by iterated Lie brackets between at most k fields in D10+ D10 ̄ generate regular complex distributions; (c) the ranks of the distributions in (b) have the maximal values that can be obtained amongst all CR manifolds of the same CR dimension and satisfying (a) and (b)—this maximality property is the total nondegeneracy condition. In this paper, we prove that, for any Tanaka symbol m= m-μ+ ⋯ + m- 1 of a totally nondegenerate CR manifold of depth μ≥ 4 , the full Tanaka prolongation of m has trivial subspaces of degree k≥ 1 , i.e. it has the form m-μ+ ⋯ + m- 1+ g. This result has various consequences. For instance it implies that any (local) CR automorphism of a regular totally nondegenerate CR manifold is uniquely determined by its first order jet at a fixed point of the manifold. It also gives a complete proof of a conjecture by Beloshapka on the group of automorphisms of homogeneous totally nondegenerate CR manifolds
News broadcast of President-elect Richard M. Nixon's and Vice President-elect Spiro T. Agnew's arrival at the White House with their families, Washington, D.C., January 20, 1969
No full textNews broadcast of President-elect Richard M. Nixon's and Vice President-elect Spiro T. Agnew's arrival at the White House with their families. Broadcast from the Statler Hilton Hotel, Washington, D.C., January 20, 1969
Instantons on hyperkähler manifolds
No full textAn instanton on a (pseudo-)hyperk\"ahler manifold is a vector bundle associated to a principal -bundle with a connection whose curvature is pointwise invariant under the quaternionic structures of , and thus satisfies the Yang-Mills equations. Revisiting a construction of solutions, we prove a local bijection between gauge equivalence classes of instantons on and equivalence classes of certain holomorphic functions taking values in the Lie algebra of defined on an appropriate -bundle over . Our reformulation affords a streamlined proof of Uhlenbeck's Compactness Theorem for instantons on (pseudo-)hyperk\"ahler manifolds
Synthesis of the First Perfluoro-spiro-bis-crown Ethers
No full textSynthesis of the First
Perfluoro-spiro-bis-crown Ether
Spiro-Conjugated Molecular Junctions: Between Jahn–Teller Distortion and Destructive Quantum Interference
No full textThe
quest for molecular structures exhibiting strong quantum interference
effects in the transport setting has long been on the forefront of
chemical research. We establish theoretically that the unusual geometry
of spiro-conjugated systems gives rise to complete destructive interference
in the resonant-transport regime. This results in a current blockade
of the type not present in meta-connected benzene or similar molecular
structures. We further show that these systems can undergo a transport-driven
Jahn–Teller distortion, which can lift the aforementioned destructive-interference
effects. The overall transport characteristics are determined by the
interplay between the two phenomena. Spiro-conjugated systems may
therefore serve as a novel platform for investigations of quantum
interference and vibronic effects in the charge-transport setting.
The potential to control quantum interference in these systems can
also turn them into attractive components in designing functional
molecular circuits
Richard Nixon and Spiro T. Agnew oaths of office, inauguration day news broadcasts, January 20, 1969
No full textA compilation of news broadcasts for Richard Nixon and Governor Spiro T. Agnew's Inauguration Day, January 20, 1969. This recording includes the oath of office for Vice-President Spiro T. Agnew, the oath of office for President Richard Nixon and President Richard Nixon's inaugural address
Hyperkähler cones and instantons on quaternionic Kähler manifolds
No full textWe present a novel approach to the study of Yang-Mills instantons on quaternionic Kähler manifolds, based on an extension of the harmonic space method of constructing instantons on hyperk\"ahler manifolds. Our results establish a bijection between local equivalence classes of instantons on quaternionic Kähler manifolds M and equivalence classes of certain holomorphic maps on an appropriate SL_2(C)-bundle over the Swann bundle of M
Vice President Spiro T. Agnew's speech at the New American Majority Dinner and presentation of awards, Washington Hilton, Washington, D.C., May 9, 1973
No full textVice President Spiro T. Agnew's speech at the New American Majority Dinner and presentation of awards to Senator Bob Dole, Senator Peter Dominick, and Representative Bob Wilson for their service to Republican campaign organizations, Washington Hilton, Washington, D.C., May 9, 1973. Includes Agnew's introduction for President Richard M. Nixon
Hyperkähler cones and instantons on quaternionic Kähler manifolds
No full textWe present a novel approach to the study of Yang–Mills instantons on quaternionic Kähler manifolds, based on an extension of the harmonic space method of constructing instantons on hyperkähler manifolds. Our results establish a bijection between local equivalence classes of instantons on quaternionic Kähler manifolds M and equivalence classes of certain holomorphic maps on an appropriate SL 2(C) -bundle over the Swann bundle of M
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