--- title: "What are the Numbers that Experiments Provide? • CBPF Index" description: "CBPF INDEX is the system that tracks the scientific and technological output of CBPF. It lists the articles, books, technical reports and other publications of the whole CBPF community." canonical_url: "https://index.cbpf.br/en/publicacoes/6ad2a767639f62b11adbb5d2" locale: en meta: "og:description": "CBPF INDEX is the system that tracks the scientific and technological output of CBPF. It lists the articles, books, technical reports and other publications of the whole CBPF community." "og:image": "https://index.cbpf.br/_og/d/c_Item%2Ctitulo_~V2hhdCBhcmUgdGhlIE51bWJlcnMgdGhhdCBFeHBlcmltZW50cyBQcm92aWRlPw%2Ctipo_Physics%2BNote%2Ccor_~I2E4MmMwMA%2Cautores_C.%2BTsallis%2Cdetalhe_1994%2Csecao_Publications%2Cp_Ii9lbi9wdWJsaWNhY29lcy82YWQyYTc2NzYzOWY2MmIxMWFkYmI1ZDIi%2Cs_zb_WhxQ1Z3EyeYF1.png" "og:image:height": "600" "og:image:type": image/png "og:image:width": "1200" "og:title": "What are the Numbers that Experiments Provide? • CBPF Index" "twitter:image": "https://index.cbpf.br/_og/d/c_Item%2Ctitulo_~V2hhdCBhcmUgdGhlIE51bWJlcnMgdGhhdCBFeHBlcmltZW50cyBQcm92aWRlPw%2Ctipo_Physics%2BNote%2Ccor_~I2E4MmMwMA%2Cautores_C.%2BTsallis%2Cdetalhe_1994%2Csecao_Publications%2Cp_Ii9lbi9wdWJsaWNhY29lcy82YWQyYTc2NzYzOWY2MmIxMWFkYmI1ZDIi%2Cs_zb_WhxQ1Z3EyeYF1.png" --- > Index of every page on this site: [llms.txt](https://index.cbpf.br/llms.txt) **Physics Note****Published** # **What are the Numbers that Experiments Provide?** **C. Tsallis** 1994 [**Download PDF **0.4 MB](https://index.cbpf.br/files/publicacao/6ad2a767639f62b11adbb5d2/pdf) [**Contact owner**](mailto:apub@cbpf.br?subject=What%20are%20the%20Numbers%20that%20Experiments%20Provide%3F) ## **Publication details**
Authors
C. Tsallis
Type
Physics Note
Status
Published
Publication date
1994
Description
On the basis of a recently proposed generalization of Boltzmann-Gibbs Statistical Mechanics and Thermodynamics, we argue that the numbers provided by experimental measurements are to be interpreted as q-expectation values <math>\left \langle \hat O \right \rangle \equiv </math> <math>Tr \hat \rho^{q}\hat O \,\!</math>, where <math>\hat O\,\!</math> is the observable, <math> \hat \rho\,\!</math> is the density operator and the real index <math>q\,\!</math> characterizes the corresponding (generically nonextensive) entropy and depends on some general characteristics of the system. The familiar association with the mean value <math>\left \langle \hat O \right \rangle _{1} \equiv \,\!</math> <math>Tr \hat{\rho}\hat O\,\!</math> as well as the extensivity of standard additive observables are recovered only for the Boltzmann-Gibbs particular case <math>(q = 1), \forall \hat{\rho}</math>, or for pure states, <math>\forall q\,\!</math>. This interpretation leaves untouched the standard additivity and conservation of energy for ''pure states'', but, unless <math>q = 1\,\!</math>, modifies the definition and additivity of internal energies for '' statistical mixtures''.
Year
1994
Number
CBPF-NF-035/94
Linked to a thesis
No
Linked to a grant
No
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