## virtual chain conditions in groups

### Remember to vote up questions/answers you find interesting or helpful (requires 15 reputation points)

In group theory, it's often very useful to know whether a family of subgroups (eg normal subgroups, Zariski-closed subgroups, ...) satisfies an ascending chain condition or a descending chain condition (that is, all ascending/descending chains in this family are finite). What I'm interested in is weaker 'virtual' chain conditions: a virtual DCC would be that given a sequence $G_1 > G_2 > \dots$ of subgroups (of some special kind) such that $G_{i+1}$ has infinite index in $G_i$ for all $i$, then the sequence must terminate. One can define virtual ACCs similarly.

Does anyone know of work that has been done on conditions of this kind, either showing that a family of subgroups satisfies the conditions or deriving consequences from them? References for analogous conditions in other algebraic contexts would also be interesting.

-

## 1 Answer

The virtual DCC doesn't seem so different from the notion of Krull dimension $1$ that I explained in answer to this http://mathoverflow.net/questions/2525/different-definitions-of-the-dimension-of-an-algebra/2588#2588 question.

-
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 5, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "english_confidence": 0.9133082032203674, "perplexity_flag": "middle"}