The importance of Pi01 classes in effective randomness

نویسندگان

  • George Barmpalias
  • Andrew E. M. Lewis
  • Keng Meng Ng
چکیده

We prove a number of results in effective randomness, using methods in which Π1 classes play an essential role. The results proved include the fact that every PA Turing degree is the join of two random Turing degrees, and the existence of a minimal pair of LR degrees below the LR degree of the halting problem.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The Importance of Π1 Classes in Effective Randomness

We prove a number of results in effective randomness, using methods in which Π1 classes play an essential role. Amongst many others, the results proved include the fact that every PA Turing degree is the join of two random Turing degrees, and the existence of a minimal pair of LR degrees below the LR degree of the halting problem.

متن کامل

Numberings and Randomness

We prove various results on effective numberings and Friedberg numberings of families related to algorithmic randomness. The family of all Martin-Löf random left-computably enumerable reals has a Friedberg numbering, as does the family of all Π 1 classes of positive measure. On the other hand, the Π 1 classes contained in the Martin-Löf random reals do not even have an effective numbering, nor ...

متن کامل

Π1 Classes, Peano Arithmetic, Randomness, and Computable Domination

2 Open and Closed Classes in Cantor Space 5 2.1 Open Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Closed Classes . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 The Compactness Theorem . . . . . . . . . . . . . . . . . . . 7 2.4 Notation For Trees . . . . . . . . . . . . . . . . . . . . . . . . 7 2.5 Effective Compactness Theorem . . . . . . . . . . . . . . . . . 8

متن کامل

TESTING FOR “RANDOMNESS” IN SPATIAL POINT PATTERNS, USING TEST STATISTICS BASED ON ONE-DIMENSIONAL INTER-EVENT DISTANCES

To test for “randomness” in spatial point patterns, we propose two test statistics that are obtained by “reducing” two-dimensional point patterns to the one-dimensional one. Also the exact and asymptotic distribution of these statistics are drawn.

متن کامل

Development of monoclonal-antibody-ELISA and -DIP-STICK immunoassays for Penicillium islandicum in rice grains.

Monoclonal antibodies (mAbs) were raised against Penicillium islandicum, a fungus commonly isolated from stored rice grains in South-East Asia. Mice were immunized by a direct, simple method; fresh cell-free surface washings from a solid agar slant culture were injected directly into the peritoneum without prior concentration. Hybridoma supernatants were screened by ELISA. Most of the mAbs rais...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • J. Symb. Log.

دوره 75  شماره 

صفحات  -

تاریخ انتشار 2010